Question for the ages...

Why do non-capital letters in blogs so infuriate so many smart people?
I get (and participate) in the punctuation, grammar, spelling and netspeak issues. But capital letters? Is it just another way to tell the wheat from the tares? Is it an effort to stand firm against the crumbling of the English language when faced with the onslaught of illiterate AOL'ers? I really want to know.

Anyone want to give me a good reason to continue slowing down enough to hit the shift key?