So, that's the thing: what did you pay for? I'm speaking specifically for SWTOR as that's a good case to work from. When you bought it, did you buy the servers and infrastructure behind it or did you buy just access to that service or did you buy a standalone product?
They aren't taking your discs. You bought that, right? They are turning off a computer they have on their end. That's their property, right? If they don't have a right to take your property, do you have a right to take theirs?
Then you get into private servers. Do you have the right to their software that they didn't sell to you?
That's the funny thing about this. If you have the right to take something from them you didn't pay for, do they get the right to take something from you that you did pay for.