I mean, I think I have made it clear it isn't a good idea for a rule, or even viable. The social contract of a group is not part of the "rules" and the "rules" don't have any control over that contract. The group can decide what rules to follow or not, so the rules are completely subservient to the social contract..I think these conversations are more productive if we don’t try to speculate about people’s motivations for starting them. So what if @clearstream us trying to reign in crappy GMing? Would that make their proposal not worth discussing? Would it change the way you engage with the discussion? Personally, I would rather just discuss what they proposed on its own terms than argue about why they proposed it.
Now, is it worth discussing for a given group? Sure. It's part of the comparison of expectations that should happen between all members of the group, not just the GM and players. But if a player made that request I would really want to get to the bottom of the reason. What does that player mean? What experiences motivated them to ask that in particular? Because that stuff is totally relevant if I am going to try and make them comfortable at my table.