Personally for me, it comes down to ignorance. I'm not aware of what pallettes people need, but if I did, I would be happy to offer them. Gimp and Photopea include color picking tools that make swapping colors around stupid easy
And we don't know what palettes "people need".
I've never heard from any Super Nintendo developers yet, despite making a SNES version of my tracks (when possible). But I've heard a lot from Atari Jaguar and Amiga developers for the MOD format version. And also a little bit from Nintendo 64 devs for the XM format they can use.
I will still continue to make a SNES version though. It doesn't take that much effort to do, and maybe some day some SNES dev will come around. We don't know. :-)