Actually, yes. "Cannot" is not always the same definition as "not being able to".
And yes, Matthew can ignore (even repeatedly) members that break the rules as owner. But don't tell me that doesn't make a mockery of said rules.
As for the bolded, well then maybe you should follow your own advice and ignore us. 
Not sure what you are talking about at this point.
You said:
It appears that Matthew cannot/will not ban him forever.
I replied to the "cannot" part, affirming that is indeed the case.
Your now distinction between "cannot" and "not being able to" is irrelevant, as you originally did not say "able to" and I did not reply to your saying "able to"..because you didn't say that, you said "cannot".
"Will not" implies Matthew is choosing not to ban him, I've already said that's his choice. His rules, not yours. He can make or change rules, we cannot. "No ban circuмventing" could have been a rule a month ago, and it could no longer be a rule today. What do you not understand about this?