Google “disco sucks” and see how many hits you get. 
I went for the 1970s, as that was when my three favorite bands – ELO, Queen, and Yes – were all at their peaks.
OTOH, there’s an awful lot of cheesy pop songs from that era. Not to mention disco. So, no decade’s perfect.
I think that '80s music was much more diverse, so that got my vote.
I did that and I got 37,700 hits.
By comparison, “rap is crap” gets 22,400 hits…
and “I Hate Rock” gets 335,000 hits.
…or here’s a fairer comparison:
“disco sucks” = 37,700 hits
“rap sucks” = 56,700 hits
“rock sucks” = 111,000 hits
“Lady Gaga sucks” = 600,000 hits
How odd! Must be some disco defenders over at Google screwing with the results.
On Bing, “disco sucks” yields 60,100,000 hits.
Proving conclusively that the stigma attached to disco is not “only in my mind.” 
Perhaps, but now I’m wondering how Lady Gaga is coping with this terrible stigma attached to her name…
Disco may have had a lasting impact on popular music, but I daresay that the name “disco” still carries some bad connotations. It’s got associations with Saturday Night Fever-style fashions and a complete lack of taste.
So yes, I’d argue that disco has a stigma attached to it–the label, not the style itself. Until recently, the same could be said for progressive rock, despite Radiohead, Muse, etc., being influenced by it.
Forget Lady Gaga. Because (according to Spoke) “disco sucks”, I fear for Madonna’s being able to eat. Because it’s been such a hard, hard road for her thus far.
RE: the whole “disco sucks” Google thing -
My search came up with 293, 000 total results. Now, I’m not gonna go through each of the pages and analyze every single hit. But the first page came up with eleven results (including two YouTube links); out of those eleven, a full seven (e.g., the majority) deal with the Disco Demolition Night event held at the tail end of the '70s, and the whole “disco sucks” phenomenon as a part of the history of that decade.
Which is pretty much in line with what I expected.
But the '80s had the good crap.
I always thought the “Disco sucks” thing in the '70s was based in thinly-veiled racism/homophobia, as it was almost entirely taken up by white classic rock fans.
I ddn’t get either one of those things out of it. The music just sucked, and it was oppressive in its ubiquity for a while, especially after Saturday Night Fever.
ETA, it wasn’t just the music, it was a whole cheesy fashion thing with the big hair and the polyester suits.
I guess it’s a matter of taste - I’d rather listen to Chic or Donna Summer than some turgid bore like “No Quarter” or something by ELP. But I’m much more a fan of rock and roll than “rock”, and disco is closer in spirit to the former (brevity, hooks and beat being of high importance to such music). I’m still not convinced there’s not some mild racism/homophobia at play, just as I’m not convinced of the same whenever people complain about hip hop sucking/requiring no talent.
FWIW, I was saying “disco sucks!” years and years before I learned that it originated in gay bars. And in any case, my all-time favorite metal band is Judas Priest, whose entire look came right out of gay leather bars (and whose lead singer’s “coming out” surprised absolutely nobody).
As far as rap goes, I was an early defender when it first started getting mainstream popularity. I was in junior high school when Sugar Hill Gang’s “Rapper’s Delight” hit the radio, and I thought it was just about the coolest thing I’d ever heard. Then rap mostly vanished from “white” radio for several years and I forgot about it until it started getting played again in the mid/late '80s. I enjoyed a lot of the early rap acts, and took a lot of shit from the people you mention. “Rap is for people who can’t sing!”. But even then, I could tell the good (Grandmaster Flash) from the pretty good (Heavy D) from the bad (JJ Fad, anybody?). Nowadays I don’t hesitate to call a rapper “bad” if I think his stuff sucks, but I compare rap to rap — I don’t compare rap to progressive rock 
Oh, I have no doubt lots of people just don’t like disco or hip hop as styles of music, period. I just always felt there were other rock fans whose motives were a bit more suspect.
MTCicero: I played *Regatta de Blanc *, and while it has more punk influence than I had hitherto thought, “it’s still rock and roll to me.” YMMV
Eighties for the same reasons, the music spoke to me.
I pretty much listened to rock in the latter parts of the seventies, and dance in the nineties, but neither pre and post decade captured the optimism of the 80’s in my opinion.
Declan
'70s. I didn’t even have to think about it. I think the music was just more varied and interesting than the music of the 80s. Funk, disco, soul, country, folk, arena rock, southern rock, prog bands, punk, bubble gum, boy bands, trumped-up nightclub acts… all these and more had great success in the 70s.
Don’t know where you’re getting that idea. Actually, I associate the “disco sucks” phenomenon more with the budding punk movement of the late 70s. That’s where I mostly saw the “disco sucks” T-shirts. And racism and homophobia had nothing to do with it. The movement was generated because, well, disco sucked.
But let me put a finer point on it: disco sucked because it was lyrically uninteresting, and musically repetitive. Lyrics are a necessary half of a good song to me, and they were almost disregarded in disco. It was all “shake your booty” and “get out on the floor” and “fly robin fly.” Yawn. And like most dance music disco had that steady thump, thump, thump which is great while you’re on the dance floor but gets really repetitive and tiresome when it is blaring from every radio in the nation.
Don’t even get me started on the fashions. Or the sad cocaine obsessions.
And for those who don’t get that there is a stigma attached to disco…really? You haven’t noticed that? I can only point you to Disco Stu on The Simpsons and hope (for your own sake) that you don’t see too much of yourself in him. 
