Axel-
Well, it clearly has been abused, though not in the way you suggest: I don't think people have used it to deliberately obscure attributions (except maybe in the recent case on the French Wikipedia). People have changed nicks around and have used nicks with non-printable characters however.
I agree with you on this. However, I fail to see how we can reach consensus here, since there are obviously quite a few people who enjoy using the feature, and in all fairness, they would have to be asked individually if they agree to it being disabled. Since you are categorically opposed to voting, I note with a wry smile that a decision in your favor will probably not be forthcoming ;). Of course you could still try to get Jimbo to declare a state of nickname emergency.
Regards,
Erik