while it would be so much easier if it would be a pull market
Uhm. It would be like asking small kids, what they would want to eat.
Also, effectively there are so many games that people already can pull the games they like. And how would that even work, if only the games get realized, that a majority voted on? What kind of games would we get? Macaroni&Cheese pizza with chocolate chips baked in?
Anyways, I believe that it would just be a push market with extra steps. Instead of a dev pushing their own original ideas (or copying and catering to existing known formulae), they would push the ideas of a small subgroup of gamers from some voting board.
Of course it would be a nice source of inspiration, but I highly doubt, it would be as effective as you might think. The problem is idea development. You do not know if an original idea would work, until you tried it. Just look at something like idle games. Imagine a pitch about such a game before the success of Cookie Clicker.