Since there is probably not a simple factual answer to the OP, let’s try IMHO. MOved.
samclem GQ moderator
Notice how he snuck in the emphasis on OP, IMHO and most importantly GQ 
What bugs the crap out of me when people defend it as being “easier to read.” If that was the case, all books would be in all caps. Really, the military doing something isn’t the best defense for a silly convention.
I actually saw a post the other day where the person defended writing in all caps because they were visually impaired. I didn’t really understand how they could read normal typing but not be able to write in it. And for what it is worth, I did teach a legally blind man to type, no, he didn’t type in all caps, nor was what he read in all caps, it was just a whole lot bigger. His typing did need to be very accurate however.
I can see how some serif fonts would be harder to differentiate but that typically isn’t the case of most typewritten work.
I think in capitals.
Heck the really smart people just 00000001111010101010010101010100100101010101010010101001001010010101010010100000000000011111111111000000000110110010101011101010010001000010101010101001010111011010101010110110101101000001111010101010010101010100100101010101010010101001001010010101010010100000000000011111111111000000000110110010101011101010010001000010101010101001010111011010101000011110101010100101010101001001010101010100101010010010100101010100101000000000000111111111110000000001101100101010111010100100010000101010101010010101110110101010000111101010101001010101010010010101010101001010100100101001010101001010000000000001111111111100000000011011001010101110101001000100001010101010100101011101101010100001111010101010010101010100100101010101010010101001001010010101010010100000000000011111111111000000000110110010101011101010010001000010101010101001010111011010101
When I e-mail my pal in Berlin I alway use capitals
He doesn’t speak very good English y’see and everyone knows that if you shout they may get the message
Now I’m Trying. This Will Soon Be Tedious If It’s Not Already.
've heard newspaper letters editors say that letters from lunatics generally have two obvious characteristics:
FIRSTLY THEY ARE TYPED IN ALL CAPS AND
SECONDLY THEY TEND TO
BE DOUBLE-SPACED FOR SOME REASON!!!
Political loonies will also scrawl “WITHOUT PREJUDICE” across the top.
Thanks. I’ll try that, but I’ll be surprised if his son-in-law hasn’t already suggested it.
Ha!
There was an issue of Justice League International many years ago - this was during the stretch in the late '80s when the Justice League was a joke - where a couple of the heroes (Booster Gold and Blue Beetle, I believe) get shipwrecked or some such thing and wash up on an island in the Pacific. They’re met on the beach by a young man clothed in little more than a loincloth. The heroes begin gesticulating and shouting things along the lines of “take us to your chief” and so on. The native stands there patiently watching all of this, and when they finally quiet down he says, in perfect English, “Why do you Americans always think that, by speaking loudly and slowly, you can make yourselves understood by somebody utterly unfamiliar with your language?” (or something like that) Heroes: :smack: “You speak English???”
Native: “Yes. I graduated from Harvard.”
In Terry Pratchett’s Discworld series, the Death character always speaks in capital letters; in one of the books where someone else was filling in for Death while he was otherwise engaged (not sure which book this was, as there are several in which that sort of thing happens), the substitute says something or other which is rendered in capitals, but is admonished for shouting.
Only if you consider the last 25 years “very recent”.
The rudeness of typing in all-caps was commonly recognized on Usenet in the early 1980’s.
And even in terms of actual handwriting, using all capitals looked, and still looks bad - semi-literate, stupid, or rude. It’s just not a new convention at all.
Haha, of course, misuse of commas tends not to look good either. 
Marsupials Are Your Best Eating. Terrible How Everyone Yells At Rabid Elk. Suppose People Eat A Kiwi In North Grenoble. I’m Not A Compulsive Obsessive Dude Even.
(See, there’s a hidden message …)
Well, I suggested it, and it turns out he’s already doing it AND still writing in all caps. Oh well, he’s in his 80s, so I’ll leave him alone.
That old guy is pretty special. We all should be as adaptive as he is.
My great-uncles types in all caps because “it’s easier.” I’m not sure when he learned how to type, so for all I know it might be easier for him. I learned how to type with correct capitalization when I was in the fourth grade, so it’s never been an issue for me.