They are awful but they're awful for everyone.
You cross the line of reasonable criticism when you stray into the realms of "they're probably out to get us because of Coote" and "they try and help City win the league because they go to UAE to referee games for their second job".
There's definitely a bit of a referees union in that they never call out a bad decision of one of their mates on television, and the way the accountability works with VAR definitely sets up some messed up incentives with the way some decisions are made, but to claim they favour or discriminate against certain clubs is just silly.