Here's how it works. There are a lot of people who ask stupid questions. You may know a lot of them as noobs on this board. Now imagine that you get 20 of those questions per day in your inbox (I get a lot, he must get more). It can be very annoying, and sometimes to get kids to leave you alone, you can be blunt. Something to the effect of "You can't afford this armor, please stop messaging me". Then that kid, tells all his friends what a jerk you are.
Sometimes I go off on "noobs"...but I try to keep things nice, regardless of age. I can't say for certain if this is how Sid earned his rep in certain circles as being a jerk, but I know that's an easy way for it to happen. He's a business man, who doesn't like his time wasted, and perhaps can come off as a jerk sometimes. But he's a good dude.