> The developers of Wayland (who are identical to the developers of Xorg) aspire to more of a Windows/Mac-like ecosystem for Linux, in which standardization, performance, and support for modern graphics hardware without hacks or workarounds are prioritized over proliferation of niche window managers and toolkits

Is that why they arranged things to ensure that the Wayland world would always be split into GNOME, KDE, and everything else (in practice, wlroots)?

That issue is more naivety than anything else.

At least some ideas that were floated early on are deader than dead, like copy-paste as DBus Service