We do.
It's one of the rules.
I kinda like threads like this. Someone sees a list of rules and says "you know, this site has been around for eight years but man, fuck their rules, I KNOW BETTER, CAPS TIME BITCHES!"
Actually, nobody reads the rules until a mod gives them sass back, then they get all pissy about it and make dumb fucking threads like this one.
Threads with all capitals are used by moderators to alert the members of the site to something important, not that whatever stupid shit you were going to capitalize isn't awesome though.
Spoiler alert: It's probably not awesome.