Back in the day you usually had young dudes taking a shot at making games, willing to take risks. Those guys grew up, oftentimes started their own studios, stopped playing games, and absolutely refuse to take risks because now they're betting their retirement funds and mortgages and what not. I know cases like that personally – people who determine the game's design, despite not having played a game (outside maybe some AAA slop) in 10+ years, believing themselves to be hot shit since they made a hit 20+ years ago. And I see young people with tons of great ideas in the industry too, only rather than making their dream game from a garage somewhere, they go work into studios to gain experience (and money). Then they buy a house, start a family, have kids, find they have no time for playing games... and the situation repeats.
You can't be a good game developer if you don't play games, it's that simple – you'll get professionally stunted, not encounter new ideas, and forget the old ones, until you just start copying mainstream shit.