I just doubt these users are ever going to care about setting up their own snap server, and if they do, they will quickly find out it's not possible and just sw

I just doubt these users are ever going to care about setting up their own snap server, and if they do, they will quickly find out it's not possible and just switch to something else. (For example, plain old Flatpak is in the Debian and Ubuntu repos) That "must not be so buggy that we refuse to support them" is a requirement for all packages that Debian ships, the difference with the nonfree packages is that if a breaking bug happens, the only real option there is to delete the package until the vendor fixes it.