Ah, so there's a name for it

Thanks to ENworlder Rystil Arden for helping expand my vocabulary of gamer jargon:

Oberoni's Fallacy states that no game material can ever be unbalanced because the GM can rule 0 it. Baloney. Of course you can Rule 0 it, but that is not an acceptable excuse to apologise for blatantly unbalanced material in the game products you pay for.

In case you're out of the loop, Rule Zero is the term given to the basic premise that the GM is the final arbiter of his or her game. I first saw it in print labeled as Rule 0 in a Guardians of Order product, but the idea goes back at least as far as Gygax and Arneson.