Strat aboose is about the only valid reason suggested so far.
I thought the first half was a valid reason too. If someone comes on and TK's and DC's then Reconnects with a separate name and does it again it would make it just a little bit harder to keep track.
If you saw someone break a rule once, you wouldn't report it (For the most part) If he keeps coming back with different names then he will never get punished for it. Admins IG would not be able to tell if it was the same person at first glance either.
It would just make the job as an admin that much harder. I really don't see the problem with the system we have now. Skip the Fun can change whenever they like now, why not do that?