Funny that you claim increased stability and integration, because one of the issues I have with my AMD card is that when it crashes, it takes the entire system with it, while if the nVidia card crashes, most of the time I just need to restart either the driver or X.
As for installation, I use Gentoo and Funtoo, and last I had troubles with that was back in... 2007 or 2008, which is 14-15 years ago, so I do believe a lot of the issues come down to how distros handle things.
As for removing support for old cards, AMD sort of has a similar issue, in that support for old cards has to be backported in, because it wasn't there.
Once again, the breakage drama seems to be more distro dependant, and some of that might be ideology-related and could thus be deliberate breakage. Solution to that is to use a less shitty distro.
And here's the thing, many heavyduty users, not just pros but also hobbyist, find a lot of use in the features nVidia provide
As for your mentioning programming professionals, I have said for many years here on Slashdot that most programmers overstate their need for massive hardware, and disparagingly underestimate the hardware needs of non-computer geek/non-programmer hobbyists. An example: My brother is not a computer geek, but he'd happily accept any time I could get him on a supercomputer, because it'd be helpful to him when he wants to run CFD and FEM simulations on the boats he design. (incidentally, he's the one who gave me his Radeon Pro WX, because it crashed too much for him under Linux with AMDGPU).