Developers should play the game they're developing.

They have to play the game to test their work, AT work.
My roommate works at a Kentucky Fried Chicken restaurant. He has not eaten fried chicken in four months because he can't stand the smell of it now.
Same concept. When you are doing something all day long for your work, most people don't wanna come home to it as well.
They don't have to play the game- that's what we do. Then we give feedback.