Scribus doesn't "deliberately" break compatibility; it was completely unusable with Wayland and they added friendly message. It also doesn't really go out of its way to do so as you're suggesting – it just checks Application::platformName() == "wayland" and that's it.

Maybe it's better now with Wayland and that check can be removed. I don't know.

See: https://bugs.scribus.net/view.php?id=16998 and https://github.com/scribusproject/scribus/commit/74d8d7ef7