It's asinine to think they are just playing the games - QA has complex skills necessary to succeed, from technical writing to careful test planning to cross organizational planning. QA is some of the least rewarding and most difficult work in a games studio.
It's like asking why camera operators in film sets "get paid to watch movies". We've decided we like games, so we better pay people for the labor in making them.
Fuck off with this "it's an honor" bullshit. It's work. It deserves good working conditions.