People who think the game doesn't cator to evil characters just have a really childish definition of evil.
Evil people don't go around terrorizing and pissing everyone off, because only in a video game that is built to let the player succeed no matter how stupidly they play will anyone ever get away with that for any length of time.
If you offered someone who's actually evil and not just hollywood muhaha evil an opportunity to be the savior of the world they would absolutely do it, then abuse the hell out of all the power and respect that brings them.
Don't be absurd, it's that the gameplay options given to me in the Dark Brotherhood have me running around killing people I'm supposed to be motivated to save. I tried running the whole "cool, I can use dragon shouts, this will help me be a bastard" RP thing and it just feels forced in the concept of the game.
I absolutely loved playing the game as a stealthy type, it's far more tactical and enjoyable, like playing the game Thief in an Elder Scrolls setting, basically a dream come true for me but I digress, just trying to share my opinion on the situation. I'll probably wait for mods to come out. I'd like to just use dragons swooping down as an opportunity to steal and murder, but I can't because they'll kill so many NPCs that I have to kill them, then the guards cheer, and I don't feel very much like the dark underbelly of society I've been trying to roleplay.