This is ridiculous
Maybe. Just because you don't know of a good reason doesn't mean there isn't one.
This is clearly and obviously unfair, unjust, hateful, bigoted, discriminatory and draconian
It's not quite so clear and obvious to me.
Unfair: maybe, but we really don't know their reason
Unjust: doesn't this mean the same thing?
Hateful: it doesn't ...
Depends where you are
eBay does not have the same terms and conditions worldwide.
In the united-states, yes. Term 4 concludes with:
The foregoing does not limit or impair our right to refuse, modify, or terminate all or part of our Services to anyone, or to terminate this agreement with anyone, for any reason at our discretion.
In australia, no. Term 4 is ...
Yes, they are.
A business can decide not to do business with someone for pretty much any reason. The obvious prohibited reason is due to your race. But I don't see how eBay would even know your race.
Some State laws might protect you, but I don't think there's any that applies in this case. For example, California might give you a means of appeal if someone ...