I think there's two perspectives here: one as a potential contributor, and one as a "simple" user.
as a potential contributor, sure, the language of the tool matters. something breaks and you go investigate the source files to figure out why and maybe open a PR. In that case, a different tech stack is no good - you'll have to learn a totally new language!
however as just an end user, I see no problem with something being written in whatever language. regardless of the implementation, all I do is open GitHub and file a new issue (if that). I don't care about whatever stack is being used, I never even look at it.
so it depends on your approach to your own usage pattern. aside from those options, I would expect any sufficiently well-designed tool to not require me to understand language of implementation to know why some particular invocation didn't work. and of course in the ideal world, if you use it and it works perfectly, then the question is immaterial anyway.
I have not looked at the source for 80-90% of the python packages I've used. if a tool is well-maintained, I don't care about its language if implementation. while I agree with the caveats you suddenly introduced in your last sentence, none of them apply to any of the tools you initially mentioned (uv, ruff, pyright) so I think you're actually arguing two different things and don't want to be convinced otherwise.