All Caps are GREAT for emphasis on words, but when you type whole paragraphs with them you basically make it so nobody will actually read or comprehend what you're saying. It's tiring to read whole paragraphs written that way (a point illustrated in the article I read, I about went nuts trying to read this long all-caps paragraph he wrote), and it takes a great deal more concentration than normal reading (and more than most people generally give to a message board). So, maybe it doesn't mean you're a moron (perhaps that was a bit harsh), but it certainly means you'll be ignored by almost everyone. Those who do manage to read the whole thing will not be able to comprehend it by skimming; they'll have to concentrate a lot more and will generally tire out before finishing.
I actually forgot about Zanex, but that's because I never read his posts because they're in all-caps.