I was convinced he took the job based on transfer promises, but you are 100% right he has left a better job to go there, he must be getting a canny monthly pay rise.
It could well be that simple, he went for a pay rise. But it's ridiculous short termism, because he's blowing what rep he had, some desperate PL club would have given him another chance, I'm pretty sure of that, or at worst a Champo team with actual money to spend.
Doubt his rep will take that much of a bit of he can't save them. Already fucked when he took over, no money at all to improve them. He'll get his high wages and leave with his rep (for what it is) intact imo.