I don't get the hostility towards Mansour at City. He has put a fortune into the club and the surrounding area, created loads of local jobs and kept ticket prices lower that City's peers. What's not to like in that regard? City's wage bill is only 10% higher than that of United.
Because UEFA threatened to ban City from next year's CL whilst the case was rumbling through the courts, so City decided the fine was the lesser of two evils.