Rooting for the Bad Guys

What, I ask of you, is wrong with rooting for the bad guys? Or rather, not necessarily the bad, but the cynical, the self-centered, and the ones who know what they want and how they are going to get it.
Frankly, I feel that those are the most interesting people of all. They rarely tend to have the same sappy ideals of the protagonist, of love, hope, and all things warm and fuzzy. Instead, these are the radicals, the philosophers, and the ones who make the first move.
I see nothing deplorable in that. Really, what is the difference between Buzz Lightyear and Hitler? Hitler was a brilliant leader. He managed not only to get others to believe what he wanted, but he even got them to act upon those beliefs. Buzz Lightyear was an equally charismatic leader, and ideologically, what really is the difference in the personalities of these two?
We glorify the nice people because their actions tend to benefit society more. Ok, fine, I'll give them that, but at least let me sympathize with the bad guy who is hated by all others and will not be getting the happy ending.
When was the last time you attempted to imagine the glorious history behind these characters in fiction? I will give you my answer: today. In Julius Caesar, I
These guys are the wittiest, the smartest, and most courageous of all, because they chose to cross that line between glory and infamy. That's why I love them.