Oh, it's a tired argument we don't need to have again. But I'll say this, your logic is based on a priori reasoning: Martin sucks, therefore good results must be attributable to something else, while bad results must be attributable to him.
In point of fact, you are describing a situation where the Habs have gotten the most out of the players they have. In any normal world the coach gets some credit when that happens. What are you saying, that with Muller as coach Cammy would score more goals in the playoffs? Gill would have been better on the PK?
As for whether Trotts or Muller would get superior results, meh. Trotts is another coach on a team where the team seems to get maximum overall results given the talent at hand; if he gets credit for that, then so should Martin. As for Muller, this is just pie-in-the-sky. Maybe Muller will make a great head coach some day, maybe not. Claiming that he's better than Martin is based on absolutely nothing.
People hate Martin for three reasons. One, they obssess over relatively minor questions like who should be on the third line at the start of a game in October. Two, they see his boring persona and hanker for a flashier personality. Three, they have a fantasy about some Coach Saviour (Muller, Boucher, etc.) who will come and work miracles - i.e., get better results than a semi-finals appearance and driving the Cup champs to Game 7 OT. All I care about is results and JM has delivered.