You're right he's a coach that has been successful even before he came to Barcelona then came to the league and won it with Barca on his first season I don't think any football lover would hate such a coach he's the type that a fan of a big team that's not doing very well would love if their team signs him cause he'll make changes immediately he arrives.
but no one here hates him, it's a question of consistency, the fact that there is a lot of pressure on him as on other coaches can lead him to make mistakes and I think it's the same thing as Xabi Alonso at Real Madrid, it's the same thing, he still has to prove everything, let's give him time to judge the work