I understand your point but in this case I happen to disagree. There is no shortage of criticism but the supporters are hardly in open revolt, the Emirates is still sold out, there is a waiting list for season tickets etc. Wenger will always keep the team pretty competitive and he's incapable of looking at his players objectively so the turnaround in players and the knock on financial cost will always be low.
There is no downside to keeping Wenger beyond knowing that you won't challenge for the PL or CL and Kroenke clearly isn't bothered about that or he wouldn't have given him a 2 year extension.
The difficult thing in this case would have been to take a chance on a new manager, new approach to transfers, new style of play, knowing that it could go wrong but also that we might actually challenge for the PL/CL which is all that the supporters you so easily condemn really want.