You’ve mistakenly conflated the Self Hosted community with the FOSS community. There is a lot of overlap in interests between the two, but the venn diagram of those communities are not at all a circle. UnRAID isn’t an exception to self hosting, it’s a textbook example of selfhosting.
It’s a similar thing with the SH community and HomeLabbing. All home labs are selfhosted obviously, but home labs are sandboxes for learning, testing and prototyping. A raspberry pi that runs one service your home depends on that you don’t tinker with outside of updates isn’t a home lab.