Koeman was doing OK at Southampton which is presumably why we went for him, and why probably the vast majority of fans were glad to have him, until now of course. It is not surprising that the owner will back him; as said elsewhere we are not like Crystal Palace, or others who go through 9 managers in 7 seasons. Even if there were a queue (which there is not) of successful unattached managers begging to be hired by Everton, this is not the time to change the manager. The names put out by angry fans to be his successor are just plucked at random from the latest media crap, without the slightest idea of their suitability, an almost certain recipe for disaster.
Sadly, it now appears he was riding Pochettino's coat-tails, much like Martinez was riding Moyes's, albeit more successfully.