I for one don't understand the big gripe against Cap's, it all reads the same to me just the letters are bigger!!!
No you understand it, it's people making their messages bigger and louder than everyone else. It has to do with one individual player feeling it necessary to be louder and more obnoxious than the majority of the well behaved and respectful players.
Sometimes it's ok, like "ALERT 123" or "MISSION UP, NEED MORE C47 PILOTS". But one individual doing it repeatedly is annoying to everyone else. If people are paying attention to the chat buffer, and if you're a player chatting about something important/interesting, then your message will be heard. If you aren't getting any responces then it's probably not important enough to retype in caps. I
It's like those kids that
have to scream, they repeat things louder and louder, things that nobody else cares about or has the slightest interest in. But that kid will just stand there and keep repeating it, louder and louder and louder until you finally turn to them and say "that's nice", pat them on the head and give them a cookie. And that's what players who constantly type in caps are doing, annoying kids talking about things nobody else cares about, grasping for attention and their cookies.