They believe this should be the task of the window manager, rather than of the protocol. They're not wrong in that, DEs like KDE have features like window zones which need so much more to work right, and tiling WMs don't need any of this, so it does make sense to keep complete implementations of this stuff out of the wayland spec. The issue is just that they take the GNOME stance and rather than make it easy for DEs using wayland to implement new features, they just say "not our problem, fuck off" and then try to plug up whatever hole the DE devs were using to make things work in the first place.
Haha, no. GNOME's problem is devs insist on making their own perfect desktop and then removing any opportunity for plugins to let users customise it to fit their wants instead. Mac is nothing like that. A Mac is a super polished experience out of the box, but Apple put up zero barriers against modifying it with plugins and third party stuff. Yeah macOS is missing some nice-to-haves like window zones, and I actually agree that's pretty bad, but it's an easy matter to install Moom or Rectangle. GNOME on the other hand would look at what Moom or Rectangle was doing behind the scenes, declare that this is "not intended functionality", and block them from working.