Yeah, but most software updates have so many bug fixes and performance improvements it's unreasonably expensive to give people a justification for each upgrade

Yeah, but most software updates have so many bug fixes and performance improvements it's unreasonably expensive to give people a justification for each upgrade request, especially when - as noted - customers accept forced upgrades without any notice at all, when something isn't self hosted. I think this is a fundamental issue with the software world: there aren't enough skilled sysadmins left anymore (how many people even call themselves sysadmins these days), so the more options users have the more ways to get things wrong they'll find. The vague, open ended nature of "support" means it ends up being an unsatisfactory experience. When the only people who need support are the in-house devops team, it's a lot easier. Unfortunately there don't seem to be good solutions for this. If users aren't given choices, they may leave or never turn up at all, but once that pain is over they won't be unhappy again (unless you have a major outage). Give them choices and when things blow up they'll become an angry unhappy customer with a support contract, which is every businesses worst nightmare.