There are certain players who are polarizing figures. These players, for whatever reason, cause people on both sides of the fence to overly defend said player, or overly bash said player.
It is very interesting to notice the polarization. Certainly I contribute in the discussion, I dislike Serena for the reasons I have mentioned numerous times in various threads, yet I will not bash Venus to the same extent. Other players polarize, as well (to be fair, it is often the fans who polarize, not the player).
Some players, for whatever reason, do not polarize. Other than one or two posters, very few people 'hate' Steffi Graf, Michael Chang, Stefan Edberg. Each played the game well, with dignity and class.
Also, very few 'hate' players who are not at the top. Robin Soderling is an example - an outstanding player, but one who does not seem to polarize.
Some players are polarizing due to the media attention they receive. Maria Sharapova is an example - some 'hate' her due to the overdone media attention she receives.
I try and be objective with players I dislike. But none of us are perfect. With some players, we cannot put our finger on why we dislike them. I was like this with Verdasco - I could not stand him, and finally I took a step back and asked myself 'why'? When I had no answer, then I found myself disliking him less. I think we all can do this. If we have legitimate reasons to dislike a player, then it is fine. If we do not.....then perhaps it is time to reevaluate.