What complaint? Why do you think I'm complaining? I wanted to know what's so fundamentally wrong with X to warrant a massive developer effort to replace it.
Based on the comments here, I have my answer: Nothing's wrong with X. Also, something lighter weight is desired for embedded platforms.
Some fraction of the population, like you, wants their display system to render in terms of points, not pixels. To me, and many others, this would be hell, but hey, different strokes for different folks -- good software does what the user wants, not the developer's will.
> ...majority of users that want sane...
You troll. :P I think the majority of users want sane display systems that don't resample and change resolutions away from the native resolution of the hardware. To you, the majority of users want fuzzy text and ugly UIs. We're both wrong to assert this as some obvious fact, because neither of us speak for any user but ourselves!
If I have any complaint (which, again, I'm not sure if I do!) it's that I don't appreciate my reliable computing setup breaking just because some young developer decided the programs I use are "too old".
This does not work smoothly at all in X11. This is a mixed bag with Windows because of reasons that are well documented. The compromise chosen by Apple works reasonably well.
This is not about my personal preferences unlike the GP asserts, it’s based on observing hundreds of deployments in industry and academia - which both Apple and Microsoft are very much aware of - they don’t try to support these features for no reason at all. I personally don’t love the scaling done by Mac OS, and in an ideal world apps would just magically scale geometry and “do the right thing”, but that is a fantasy land and the best FLOSS unix has to offer with X11 does not meet a lot of users needs.
As for nothing wrong with X? Lol this is a display system that still does not have a sane unified way to prevent screen tearing - despite 30 years of shitty attempts.