Yaya is still arguably our most influential player, we consistently fail to do anything when he's not playing.
The problem is that he's 32, doesn't have the stamina to play the box-to-box role in a 2 man midfield Pellegrini wants him in and thus he gets exposed. With a manager like Guardiola who will set up a midfield properly and not ask him to do the running of 2 players, he would still be a fantastic player - as evidenced by his good performances when we've had a 3 man midfield in europe this season.
If he is willing to take a smaller role in the squad, one where he's not playing every game, and the appropriate pay cut then I don't see how any City fan could be upset with the idea of him staying at the club.