It's the alignment of "whatever I want to do," and I suppose it works to a certain extent. But it's one of those alignments that everyone really likes for some reason, and I really think that reason is that it's all about random amorality.
Neutral is a similar boat, but that's somewhat more manageable given that it's all about balance. If you consistently play a neutral character too far to the left or right, then you're not really playing a true neutral character.
The odd thing is, I don't have much to complain about in the games I'm running (well, I suppose I do, but I won't get into it). But going over first level characters, I'm always wary when I see "CN" scribbled in for alignment. Most of the time, Chaotic Neutral is played like Chaotic Evil Lite.
Anyway. I think it's more challenging for players (including myself) to take some kind of moral stand. Even if it's "Evil," it's still something. And while Evil PCs tend to lead to lots of inter-party strife, they can also add an element of fun insofar as character interaction is concerned. They don't need to be mindless killers.
Anyway. I'm done. Oh, and Happy New Year.