Wayland went for minmalism because one can always add things later. Unfortunately, making additions in a multi-desktop environment turned out to be kinda difficult.
In a way, the quality of the design (and implementation) is fine, but the quantity of features is insufficient and limited by social issues.
Wayland is not trying to do enough. You can send pixels to a compositor - great. It turns out a desktop is more than just pixels sent to a compositor. It turns out X11 has a lot of stuff because there is a lot of stuff to do. It could be simplified somewhat, producing incompatible X12, but not simply thrown away along with all the accumulated knowledge. It's literally the Joel Spolsky "never rewrite Netscape" effect in action. Wayland has now spent nearly a decade reaccumulating a part of the same knowledge that was already known, but worse.
wayland annoys the toxic people, because it is currently favoring easy alternative implementations.
It won't last, probably.
Those toxic people usually always get their way into "core", pouring tons and tons of interfaces and dirty everything, viciously adding "features" to provoke some level of planned obsolescences over some few years cycles.
I'm not sure who you are being sarcastic about in the end, but yes, Wayland is indeed clean and simple enough to not particularly discourage alternative implementations.
For example, it's vitally important that wayland resists adding features like title bars, window icons, resize handles, desktop icons, or mouse cursors. These frivolous features have no place in a serious desktop environment! They are only bloat!
"tantrums" is when you expect windows to be delineated with borders apparently. You got the Wayland attitude down pat: are we the problem? No, it's the users who are wrong!
In a way, the quality of the design (and implementation) is fine, but the quantity of features is insufficient and limited by social issues.
It's basically the opposite problem of systemd.