Hate him all you want but he'll bring United success and trophies.
Be careful what you wish for, Moyes is a drab mediocre manager and managed to attract one player in his first Summer(Fellaini), Van Gaal's team was the most spiritless, empty, boring team I've ever watched. Mourinho's team win consistently and (usually) win well. I doubt many other managers could have attracted Pogba, Mkhitaryan, Lukaku, Matic and also manage to keep De Gea.
As an afterthought, who would replace Mourinho and bring success?