In general you're right but with Murray it gets frustrating that everyone knows what he has to do but he refuses to do it. It's not like he's an overachiever or a fighter. If criticism will make him get more aggressive (not from these boards obviously) than give him as much as he can handle.
I think he tried to be (for him) more aggressive today but Fed defended very well. I think his problem is that he doesn't practice his aggressive mode enough in easier matches so he is less sure of himself when it comes to putting the hammer down. He might be right to play conservatively to give himself his best chance against a lesser opponent but it sort of catches up with him when he has to raise his game at the top level. Having said that, I thought Andy hit his forehand well today (for him). Still needs to work on that side obviously. Maybe his backhand wasn't consistently aggressive enough, considering how good he can be on that wing. Also, I didn't see him at the net hardly at all - obviously that missed volley on set point in the breaker comes to mind and maybe he wouldn't have missed that if he had been getting in there a bit more. But Fed didn't really allow him to play his best - he was too consistent, thus exerting too much pressure when Andy did have a slight opening.
At least Andy does show signs of continued improvement and the guy is obviously working hard and has a lot of desire. People say he is stubborn etc. but I think that can be an advantage also. He at least takes responsibility for how he wants to play and he is entitled to make that choice, though others can/will disagree.