Isn’t it possible he believes he can fight his way back into contention?
Zin and Delph did so, with some short term success.
Despite the many opinions on Stones, I’m not sure we really know him all that well.
We are (hopefully) close to signing a £65m CB in Koulibaly, who will be a lock in starter.
He then has Ake to contend with and I think Stones has fallen so far out of favour with Pep that he would sooner play a left footed Ake over him (obviously remains to be seen, but I think we will see Laporte and Ake together more than people expect).
Then he has Fernandinho who is still ahead of him in the pecking order.
From Stones' perspective, what reason is there for him to stay at City? Completely out of favour, a very good chance he's out of the England squad if he keeps up and now has two brand new, expensive CB signings to contend with when he couldn't get a game at our lowest point with our only other options being a 32 year old, slow reckless Otamendi and a 19 year old academy player just breaking into the squad.
From our perspective, I personally feel there is just zero point in keeping someone that we could likely fetch £25m+ for as a 4th choice option when we have Fernandinho, THB and Tosin that could all fill that void comfortably.
For Stones' own sake he should be the one pushing for the move this summer to get his career back on track. Him being the way he is though, I wouldn't be surprised if he is content with playing a limited back up role, so I think the club have to be ruthless as well and strongly encourage this move.