> Yes, I know about bug trackers, I have used them. However, you mentioned it was like getting a car fixed.
My point was you won't just accept that it is broken but try to get it fixed.
> So where do I go where I can pay someone to fix GNOME-shell induced graphics problems?
Find an engineer that has the required knowledge and pay him for fixing it. You can search in IRC channels or mailing list for people with the required skills.
> I don't have any confidence that just leaving a bug report in some tracker somewhere, in the hope some hacker I have no contractual relationship with will fix it, will lead to this issue being fixed.
If you don't even tell the developers about your bug chances are that it indeed never gets fixed unless someone fixes it by accident or someone else hits it and reports it.
> As for which computers don't have good 3D support under Linux, install Fedora on any NVidia system.
Done that and works fine.
> I don't have a citation to hand, however it's surely not controversial that NVidia graphics constitute a sizeable set of modern computers?
No the controversial part is that they don't have working 3D acceleration. Just because you hit a bug with your specific GPU / configuration does not mean that NVIDIA cards do not work at all. Also there is the binary driver which works as well.