Hm. I wonder why that doesn't happen?
Perhaps, under some circumstances, for some kinds of campaigns, restrictions are good sometimes?
Perhaps, players (some players — they aren't a monolith) don't always know what's best for every campaign? Perhaps, what players want and what will make a campaign good (for a certain view of "good"), aren't always the same thing?
So, the flaw is that reasoning also applies to the GM. "GM" is not a magic state that gives someone superior powers of cognition such that they always know what is (or will be) best either.
Playing RPGs is a collaborative effort, so it pays to, you know, collaborate.