There's a point where the rules simply stop working. Beyond that point, it's not really possible for a GM to run a proper game.
Now, I don't want to give the impression that I have a problem with groups that go past that point, because I don't. But those groups aren't playing the same game as the rest of us, which means that they simply aren't relevant to our discussions of rules.
I mean, you can pretty much throw out the Monster Manual once someone's built Pun-Pun (all-powerful D&D character that exploits poorly-written rules, for those who don't know) because the rules don't matter anymore. A good storyteller might be able to make curbstomping the universe fun, but the rules won't enter into it. The game ends and becomes a story, so to speak.
So please don't say "some groups like this sort of thing" when people are trying to deal with a rules loophole. It's true, but it isn't helpful.
PS: Sorry if that sounded harsh.