Campbell
Relaxed Intensity
People have stated that controls on the GM are a universal good with no explanation why. They just assert it as truth. That makes me try to guess why they believe what they do because they won't explain.
Not all games have to operate the same. In fact over the past half century the most popular games don't have hard constraints on the GM. I don't think their necessary, it seems like they don't harm the popularity and growth of games that do not have them.
Who is saying that? All anyone has ever said is that different sets of constraints can enable different forms of play that a more freeform approach is incapable of providing. That we know this because we have learned how to approach roleplaying games in different ways. It's just as true that D&D provides an experience you will never be able to achieve in Apocalypse World as the opposite.