How do you think we can get through to the anti-vaxxers?
Require mandatory vaccination. The only exemption being for children who cannot receive the vaccine for medical reasons. And if an unvaccinated child is subsequently harmed by contracting measles prosecute the parents for child endangerment.
It may be that Wayland / Weston targets Linux in the first instance (just as Linux kernel originally targeted x86 processors) but that does not preclude it from other kernels over time. If someone were to try I suspect the problem would lie less in porting Wayland / Weston and more to do with the sorry state of GPU drivers for other kernels. In the meantime, use X. I doubt it's going away any time soon.
Linux has always featured choice. Personally I dislike KDE and I am critical of it but I'm not required to use it so I don't. Nor are you required to use Wayland. Stick with X for as long as you like. Gather a core of likeminded people and produce a dist that suits your requirements. I'm sure Amish Linux will be a huge hit.
And every software is "unstable untried" until it is. I'm quite certain Wayland will have bugs in it and will fail to function in certain configurations. And those bugs will be fixed, either in Wayland itself or in the code it depends on, e.g. Mesa or display drivers. If it bothers you, don't use it until the bugs are fixed.
And what "missing features" are you talking about? Part of X's problem is it is a veritable kitchen sink of features, most of which are obsolete, inefficient or an impediment to be worked around. And that's the point - Wayland is not attempting to reimplement everything in X. I also hope you're not going to say remoting because that's the compositor's job, not Wayland's and there is a reference remoting implementation in Weston that uses RDP.
And just "some X11 developers"? The most prominent supporters of Wayland are major X11 developers who know how broken X is. Name any prominent X11 developer who is in favour of maintaining the status quo, who thinks X is perfect in its present form or can be fixed without breaking backwards compatibility or without making a complex tangle of obsolete code and extensions even more complex.
I don't see Mir as being in much competition though. Canonical have hobbled interest in it due to the restrictive licence and contributors agreement and most people regard it as divisive. I will be interested to see what the gubuntu dist do when GNOME shell is fully Wayland compatible - whether they intend to use it or if they will be constrained by Canonical and leave GNOME using X until they can port it to Mir.
Aside from the differences on paper, the actual implementations can be broken, buggy or inefficient. e.g. Some older desktop drivers might not offer an ES 2.x profile, or it could be hopelessly crap.
There is no GLU / GLUT either for ES 2.x and every platform implements its own equivalent but proprietary set of APIs. So you may discover a lot of work is required to fix that. Then you may discover that one platform or language's bindings are different from another in subtle but annoying ways, e.g. there are several OpenGL ES 2.x bindings for Java and one might return a handle in an int array while another expects you to supply a 1-element sized IntBuffer. Annoyances which add up.
In summary, yes you can port code, and OpenGL is definitely one family of APIs that offers support across a wide selection of devices. But it's not guaranteed to be simple and probably won't be. The best bet is use a good third party library (e.g. libgdx) and let the library hide as much of the work as possible.
I wonder how many people would have had second thoughts about investing if they'd seen the corpulent greaseball they were entrusting their money to.