And it is compiled by Nvidia, which is why the open source fanatics try to insist in nouveau.
No, it is not.
Nobody insists in you using Noveau, unless you're asking them to help with your problem. Anyone you ask suggestions from, if they know enough to be worth asking, will tell you that the benefit from using open source is that the developer community can help fix bugs, whereas with closed source drivers, only the vendor can help.
It is not ideological, it is purely practical. "Fanaticism" or "zealotry" is not involved. The Linux kernel has no separation or isolation between modules, and most bugs left over nowadays are complex interactions. Normal bug-finding tactics and approaches just do not work when the kernel is
tainted –– which itself is just a label applied when kernel problems become much harder to resolve; loading proprietary kernel modules only being one cause among many.
That is, it does not matter whether the bug
seems to be related to the closed-source driver or not. If one has been used since last reboot, it makes debugging any kernel problem very difficult or impossible.
For non-developer users, it is often impossible to grasp the fact that even though the end user vehemently believes the problem has nothing to do with the proprietary kernel driver they're using, because of the structure of the Linux kernel, having had one loaded at any point since the last bootup/reboot makes kernel debugging/problem solving futile.
It is even more difficult to understand that the number of end users affected are completely irrelevant to the open source developer community, because they do not contribute anything. Open source communities operate under free market rules, with useful contributions being the main currency. It is also why the number of desktop users is absolutely irrelevant to open source Linux developers: they bring nothing to the table, and are thus irrelevant.
Similarly, having stable interfaces for out-of-kernel modules would bring nothing positive to the kernel developers, only lots of extra work and restrictions on developments.
I have fixed Linux kernel bugs. I have also had to decline even trying, because the person struggling with the bug was using a proprietary driver, making it likely that any investigation I would do would be stopped at the proprietary driver black box, and thus not only make the investigation fruitless, but also annoying the heck out of me, because when I start an investigation, I want to see it through. Being stopped by a black box is incredibly frustrating.
I have also had users call me a "open source zealot" and "fanatic" behind my back because of this,
and I do not appreciate it, because I'm nothing of the sort. I often work with closed source and proprietary stuff, with Tux being my mascot, not my idol. Even RMS, the most vocal open source advocate there is, has logical and reasonable reasons why everyone should prefer open source, and is thus, by definition, not a "zealot" or "fanatic".