I don't see how open sourcing is meaningless if you don't do the things you listed.
It may be meaningless to you, but you can never tell if someone else will be able to benefit from your work.
Tiny, obscure project but it was just what we needed, after a few fixes for our use cases.
I don't know how much clean-up id did on doom's source before releasing it, but my understanding is that they didn't do that much. And I wouldn't be playing Doom today if it weren't for that source dump.
I'm not playing dwarf fortress. I kinda would like to, though.