Some people never learn indeed, but some others do learn. That's why we give chances.
Let's imagine the worst case if Lurker becomes a Member back : he messes up again (he can't harm much with a Member level if you ask me) and he is banned again. He gets nothing with bad behavior and he knows it.
Now imagine the best : he learned a life lesson and he'll be a great member. You notice what's important in your common life when you lose it, unfortunately. My life motto is to enjoy each moment of your day and each little thing surrounding you no matter what. Lurker lost his place with us and he is (at least that's what I think) regretting what he did. He knows it's his last chance and he knows that he will miss ETernal Clan again if he is banned.
It's up to our Members to decide wether he should be a Member or not after all. Just keep in mind that since the beginning of ETernal Clan, everybody was given a second (or more) chance(s).
Starting to unable people to be part of us, no matter what they did in the past and no matter who they are, would be against the foundings of ETernal Clan and thus a huge change.