Because games are the only part of our culture fat 20-samethings can claim superior knowledge about?
Because in every very closed subculture (like gamers were like 10 years ago), there are people who hilariously think they're superior to everybody else by being in it... and when the subculture goes mainstream, they lose that sense of superiority? So they claim not to like that mainstream stuff to allow themselves to think they're still better than everyone who does?
Because no matter what you name, some people who hate it exist somewhere in the world and it doesn't have to be game-related and that's just how the world works?
SO MANY OPTIONS!