I am not his fan because I think he benefits from an overall very weak era, has an ego that is incredibly obnoxious, and tries to mask it behind an "I'm so nice and humble" attitude this is so phony he could easily be a politician. Even if he wins 20+ slams I will never think he was the greatest tennis player of all time because aside from Nadal he is not playing any other great players. McEnroe, Sampras, Laver, Gonzalez (Pancho that is), Lendl etc. These are all guys I think are better players no matter what Federer does with the rest of his career.
He is a mentally fragile player that plays against weak people. Just look at what happens to him when someone dares to stand up to him. He falls apart (i.e. against Nadal generally and Canas in the last month or two).
What I don't understand is why ARE people his fan? Generally I like people that seem to be good people first and foremost. This is why I like Nadal. I like his attitude and fighting spirit. He seems to be genuinly down to Earth (before the Wimbledon final he stated he can only beat Roger "Sometimes" after the interviewer said he "always" won, and then went on to say he would have to play the match of his career to win. I like that) whereas someone like Roger after getting repeatedly spanked by Nadal goes off to say he is one dimensional and that he is still the obvious number 1. That is unbelievably obnoxious, and I don't see how a single person can root for that.
It has been my observation that a lot of the Federer fans attach themselves to him as if his accomplishments somehow bolster their own lives or sense of self worth. I find that odd myself. I know this is not unique to tennis, and is a problem with all sports, but Federer fans seems to live and thrive on his wins. I would suggest some sunshine for these people.