It really makes me wonder how Federer, the last man to play such graceful tennis, has so many haters. You aren't really a fan of tennis if you hate his game.
1) People generally can relate to (and gain inspiration from) players who rely on great work ethic, more than great talent.
2) People generally prefer humble people.
3) Federer's game is modelled on the text book. When you watch Federer vs Nadal live at the AO, it is Nadal's unorthodox shots that look more spectacular and more entertaining.
And I was a Federer fan in 2003 but quickly switched to being a Nadal fan before 2004, and never looked back.