It's interesting to see what makes people support certain players. For me it's about the way people play the game, what it looks like, what they do with the racket and the ball and how they move around the court.
We can criticise all of these guys if we choose. Popular criticism says Federer is a bit arrogant, Nadal a bit odd, Djokovic tries too hard and Murray is a bit mentally weak. Do I identify with any of these guys, not really, not because I don't have these traits, but more because I know I am very average in comparison. As an admirer of all them the one which frustrates me is Murray because you feel he could and should have done so much better.
Anyway, my acknowledgement that the 2012 Aussie final was one of the best matches in tennis history conveys my answer to OP's question.