You're right.
There are different levels of baseball knowledge and participation. Some people are new to the game, some people have ideas which differ from the mainstream, and some people are young.
All their ideas should be welcomed and encouraged, even ones that don't make that much sense. There are a few posters with the patience to point out the flaws in certain arguments in a nice way, while others seem to thrive on belittling others because they lack the baseball acumen.
While the bully posters defend themselves by suggesting that they get annoyed with all the novice and uniformed posters, the truth of the matter is that there are half a dozen forums out there, where they could go, that are filled with avid Blue Jay fans that have the same or similar knowledge of the game that they do.
But, not unlike the 25 year old kicking <ass in rookie league ball, these posters have no interest in being in an environment where the other posters have equal knowledge. They much prefer to be in a place filled with a fresh supply of newbies who they can belittle, and where they can take great pride in their superior knowledge of baseball.