A trope of the 1950’s and 60’s was kids sitting stupified in front of the TV (usually watching cowboys and Indians). Currently it’s the stereotype of a overweight, socially retarded white male engrossed in gaming.
In its time between the World Wars, was radio treated as the same sort of black hole?
We have maybe 5 active members who were around during that time, so I don’t know if you’ll get eyewitness testimony. Here are some thoughts I have, from a generation later.
My sense, from stories from my parents and things I have read, is not so much as TV. Radio was instant communication, with breaking news and events, that we didn’t have before. Even when entertainment took over, entertainment that was probably just as silly as TV, almost all the programming was live, which I think probably added some interest. Radio dramas were broadcast twice, once for the eastern half of the country, and once for the west. For other events, like sports, you had to re-arrange your own schedule or miss out. I don’t think they had the concept of “required listening” as we have had “required watching” with TV.
I think another big factor is that radio is a more active medium, encouraging the listeners to use their imagination and create mental pictures, while TV is much more passive. Radio can be played in the background, TV tends to take over. Even boring TV might keep you looking at it just because it’s visual. If radio is boring, you’ll probably ignore it or turn it off. So radio can be gripping but it has to be done well, and so I think it’s less addictive than TV.
The comparison to gaming is interesting, because gaming requires full attention while you’re doing it. I think that makes it more addictive (if you’re into that sort of thing) than either of the other activities. So it may be a menace but a less wide-spread one.
My background is in broadcasting, so old-time radio is a bit of a hobby. In the very beginning (the 1920’s), radio was seen as a pure, unadulterated miracle, and during the depths of the Depression, it was hailed as cheap entertainment. Later in the 1930’s there was concern about the commercialization of the medium and the mediocrity of the programming. But in the 1940’s radio was the most important source of war news.
What negative stereotype existed was of a bored housewife, sitting and listening to soap operas, neglecting her household chores and not getting supper on the table when her husband got home from work.
Two words–Radio Evangelists.
It started almost immediately.
You might get earwitness testimony. 
ETA:
Huh? What “required watching” am I missing? I don’t even have a TV.
Of course things in the UK were very different; we had the BBC under Lord Reith, and their motto was "*Our mission
To enrich people’s lives with programmes and services that inform, educate and entertain.*". There were no commercial channels and, thank God, no Evangelists, although there were some compulsory religious slots.
I was born during WW2 so my memories are from the 50s, which were pretty much the golden age of radio. TV was gradually taking over, but sets were expensive and picture quality poor. There were programmes which were compulsive; The Goons, Dick Tracy, Lost In Space and many others, but radio was certainly not seen as a bad thing, especially as most adults who had access to one, had relied on it for news and entertainment during the war.
If you are looking for negative stereotypes attached to radio broadcasting, you may want to look at a later era, to what adults thought of top-40 listening teenagers of the 50s and 60s, and the Alan Freed era DJs that promoted early Rock and Roll. Particularly after the advent of the transistor radio, and you had a common stereotype of kids walking around obliviously holding the gadget up to their ear.
The commercialization of radio was widely denounced in the 1920s, after the first broadcast licenses were issued. Radio was seen as an edifying institution, where good (i.e. high) culture and educational and religious programming would predominate. Herbert Hoover, as Secretary of Commerce who nominally had control of the airwaves, was a main proponent.
That worked about as well as the later similar expectations for television. The fight was lost before it began. But radio was looked down upon for years.
You don’t? Tell us more!
He said there’s some “required watching”!!! Now I’m worried that I’ll get in trouble if I’ve missed it! What will happen the Required Watching Police kick down my door, and there I am, naked in my ignorance, not only not watching, but not even knowing that there’s something there I need to be watching?
I’m not Roderick, nor do I play him on television, but I’m pretty sure the quotation marks were to indicate that he wasn’t serious about it being required, but rather referring to shows that significant numbers of people watched and talked about under the assumption that everyone watched them. This notion was epitomized in the catch-phrase “Must-see TV”
I would say this was much more a case of the general adult animus toward rock ‘n’ roll itself. Radio was certainly one (though not the only) medium by which it was promulgated, but said adults were listening to the radio just as surely as teenagers were…they just didn’t like what they heard on it when they tuned away from their sappy pop stations.
The whole payola business was framed almost more by the notion that “teenagers would never genuinely like this music if it weren’t force-fed to them” than it was any sense of unfairness in the “pay to play” paradigm.
Alan Freed was the sacrificial lamb for the entire rock ‘n’ roll radio industry, as he was a bit older and drank and smoked. Dick Clark, whose hands were just as dirty, got off scot-free because he was young, fresh-faced and a good bullshitter.
Finally, I lived through the era and maybe I missed it, but I don’t recall any particular outcry against transistor radios, either. They weren’t cheap in the beginning, so only older teens with jobs could likely afford to buy them. Anyone younger and not part of the workforce may well have received them as gifts from their parents, as I did.
For a teenager, the BBC, with some exceptions as noted above, was pretty bland and boring. I can remember on Saturday night, under the covers in my boarding school bed, listening to The Top Twenty from Radio Luxembourg on a crystal set I made myself.
The Netherlands, in the '60s, had Radio Veronica. They broadcast from a ship, offshore, as an alternative to the state-licensed broadcasters in Hilversum. Radio Veronica was very popular, because they played all the naughty pop music of the time.
I wasn’t around then, so I couldn’t really say how it was perceived. But I get the impression it was considered quite rebellious and corrupting to listen to Radio Veronica.
I have relatives who belong to a very conservative sect of the Christian Holiness movement. These people make Baptists look like libertines.
They are okay with newspapers and some radio. But not TV or movies at all. The advent of the Internet caused a split in their church. It’s okay “at work” but not okay at home for one sub-sect.
Regarding radio: News and suitable gospel stations are okay. Not the general music stations. Unfortunately, extremist “talk radio” is somehow considered news and so I’m seeing some of my older male relatives getting lost into that.
There are no radio entertainment shows like Fibber McGee and Molly anymore, but those would have been definitely out. Since those types of shows, soap operas, etc., dominated radio in the 30s and 24-hour news/talk stations were not yet born, I can’t see them spending much time in front of the old Zenith.
I recall a MAD Magazine comic from the 1960s where a father grumbles that his children “always have their ears glued to that stupid portable radio!”. (Of course the next panel shows that the children have detached their ears from their heads and affixed them to the radio with glue.)
My memories don’t go back to the 30s, but in the early 40s my father introduced me to “Let’s Pretend” a Saturday morning weekly show that dramatized fairy tales. It was a wonderful show. My mother listened to all the soaps but it didn’t interfere with her doing her housework every day. And when I got home from school, I listened to a regular string of adventure stories (Lone Ranger, Jack Armstrong, Superman, The Shadow) all 15 minute daily shows. I never heard anyone complain that these were a waste of time or any criticism at all, really. I don’t recall that we listened much after dinner. The real bete noire was comic books which were going to lead to the downfall of civilization. And when I discovered science-fiction, oh that was escapist literature of the worst sort. (It will come as no suprise that the Foundation trilogy blew my mind.}
Must’ve been Don Martin. I can picture this as being one of his. 
A number of things happened in the period from 1950 to 1955.
All of the above worked together to shift radio from a useful household family tool to a toy with potential to divert people’s lives toward the trivial.