Saying "their server, their rules" is not primitive, it's simply true.
If I buy a car, I can set in place whatever rules I want for anyone I let ride in it. Regardless of if I smoke, I don't have to let you smoke in my car, as it's my property and can do whatever I want with it. It's a simple statement which sums up the concept of ownership of any given item.
You do not have the right to play on their server, you have the privilege. Therefore, they can attach to that whatever they want.
Anyway, I think this thread has more than run it's course...