This is especially true for people that prefer low latency over tear-free rendering.
Wayland requires* everything to be monolithically built into the display server (which is also the window manager), which means if I want to use a new WM (say, XMonad) I need to reimplement all of this stuff. Want screenshots? Build it into your WM! Want redshift? Build it into your WM! The result is that development effort will be wasted reimplementing "competing Wayland implementations" stuff that no-one actually wants.
Compare X11, where I could run an Xorg server together with any of a number of lightweight window managers, and the window manager is only responsible for, y'know, managing windows, and determining how the window decorations look. Xorg handles everything else, allowing a robust marketplace of competing WMs to arise.
* Unless/until they finally give in and standardise protocol extensions for out of process window managers.
? what? you mixed systemd with wayland maybe, everyone knows that wayland is a protocol, this is repeated 100 times in each thread , everyone also knows that most of X features are not part of wayland