This one's not a "catch 22" it's a "catch 44."

First and foremost, it's their sandbox and we are all guests --- Invited guests that they have every right to un-invite at their discretion.
That being said, they then trust a third-party to administer the affairs of their site as moderator/administrator and turn over trust to said third-party who may not share 100% of the owner's values/beliefs/attitudes and who may get caught up in personal issues with members. I've seen sites lose a majority of their membership just for allowing the "wrong" person to act as moderator or administrator. Forum rules are very tough to decide upon but they are even tougher to enforce because no matter what rule you adopt, there will always be "certain" members who always seem to tread on the thin ice of breaking forum rules.

I'm glad I don't have to do it. I've read the posts of hundreds of people I would ban just for their stupidity, much less their abuses of the rules or other members.

But I do love a good burger . . .