The point of banning is to prevent you from breaking rules any further, and in the case of temp banned it can also give you chance to think about the wrong action you took and telling your self that you'll never make the same mistake again.

Now going around that means, you don't think your infraction or punishment was the right call thus spitting on the face of the moderators, and spitting on the Org rules.

Only decent reason of creating a alt account I can think of is to anonymously seek advice on private matters... and if the matter is that private and important, it should be better to ask a professional.

So basically, I don't see any decent reason to have a alt account. Its also bad because someone may want to use your alts user name.