With X11, you defaulted to having tearing but could run a compositor if you wanted in order to not have it. Then Wayland showed up and loudly proclaimed that that was unacceptable and we had to be pixel-perfect, every frame, every time. ...Then a few years later, Wayland added the ability to tear, because it turned out to be useful, bringing it back to parity with X. This isn't... necessarily... technically invalid, but the optics aren't great.
You don't understand how this works I think. The idea of this protocol is for the compositor to change how it does page flip in specific conditions. So just allowing a player, for example, to prefer visual bugs over latency on a specific game over bug free image but having everything else still being bug free. I'm not sure you know how building software works but it's called iterating. The main need is bug free rendering, which is achieved, an iteration is a niche need of buggy visual prefered over latency, this will be allowed.
