Mourinho should emulate Guardiola who takes responsibility for the poor performance of Manchester City.
The ones that are paying him 10+ million a year? That would be silly of course, so what's left, is he going to go out and say he is a bad manager himself and he is the reason why they are doing badly and risk the rest of his career? His ego alone wouldn't let him see something like that. So there is only one thing left, which is the system, one way or another, referees, or whatever else in power, must be keeping them down. This way, when you say it's the system, then you are protecting the fans, the players, yourself and management all at once.