Want to run xterm? Requires Xorg. rootless Xorg requires udev, udev turned into a systemd component. want to run xterm without systemd? good luck, you are now the maintainer of your own LFS.
I think it's true that it's an exhausting battle to keep all those parts independent when 95% of the devs/money agree it's better to integrate them. But it wouldn't be fair either for the 5% to put on the others the burden of keeping things independent because of their own preferences...
It just so happens that until recently xorg was the only game in town as far as Linux x11 servers are concerned.
Yes, but this is hardly a unique systemd/Linux problem. I despise TypeScript for various reasons, always preferred vanilla JavaScript over TypeScript. So if I'm met with "Huh, this library is using TypeScript, am I ready to deal with that", I make the choice to not depend on that, even though half of the ecosystem uses TypeScript.
Going against the grain comes with more work probably, but this is also a choice we make, because we have strong feelings and opinions about something.