Well, most gamers don't have more than one or two consoles. They usually therefore attach themselves to their consoles' offerings, whatever they may be, rather than genres. A Pokemon fan would be lost in a JRPG section. A PS3 user with LBP - what's he to do in a platformers forum where most of the games being talked about are for Nintendo consoles he doesn't own? Also, arranging it this way makes sure that people who'll be constantly visiting the forum will read about games that they may or may not have, but can get. Even if I like racers, reading about GT5 ain't gonna do me any good, but, even if I dislike dancing games, I may decide to go for Just Dance if I see people discussing it.
“These are my principles; if you don’t like them, I have others.” – Groucho Marx
