My point was that if you are a good player and are given the central role in the team you will always produce good numbers. For someone like Rooney who takes most free kicks, corners, historically penalties and plays in the most statistically efficient role, of course he is going to get 40 goals+assists a season.
However we all know he had a poor season last year. This is as close to a fact as any opinion could be, despite him still being efficient. This doesn't mean he was one of the top 5-10 player's in the League. The likes of Mata, Hazard, RVP, Carrick, Bale, Benteke, Cazorla, Rafael, Zabaleta, De Gea, Suarez, Baines and probably a few others all had much better seasons. This year there has also been a similar number who are outshining him.
He should be consistently in the top 5 best player's if he wants to be paid as one of the best in the World (let alone the League).