Game Through Consensus

I love playing with players who are new to the hobby. They have no preconceptions. I try to run my game as much as possible by consensus. Whether it be the crunchiest modern system or the lightest OSR system consensus is the aspiration at my table. Collaboration is the only vehicle to a successful game. As I play with new players more I find that they are more open to the collaborative and consensus driven nature of my game. I find that often the more exposure players have had to role-playing the less they are interested in the group story. I don't know why this is. Maybe as players gain more experiences they become more particular as to what they want the story to be about and stop listening to the others at the table (or even the gamemaster)? Or maybe it is just that they have had a lot of non-collaborative roleplaying modeled to them, so they have become habituated to a different style of game - whereas the new player learns from what I model and suggest which may be quite different?

In either case how can we rescue the veteran roleplayer?

I also wonder if this is a problem I face alone, but my experience as a teacher tells me that a problem one person is having is often just the tip of the iceberg.

Anyone have any thoughts?