I think in a lot of cases it is not really the name its self, it's the sentiment behind it.
Probably, a majority of people who come up with 'inoffensive' versions of offensive names do so, at least to a tiny extent, becuase they get a kick out of knowing that a hundred or so people they anonomously run past in a city that day will understand what they mean. And some of those people probably get a small kick out of the fact that out of that hundred or so people, three or four of them might be slightly offended. Those are the people that these bans are aimed for I imagine.
There are cases, like Leprekan's example

,where I do find them to be amusing becuase they do require a bit of thought. However, more blatant names I do find a bit offensive, and I think it's a bit funny when those sorts of people get caught and punished for it considering how incredibly mild the 'punishment' is. If it was a permanant ban I wouldn't find it amusing in the least, except for the most offensive of cases. However, considering that all they do is lock you out of the character and give you a chance to rename, I don't quite see what the harm is.