Huh? We reboot our servers all the time. We would never design an app that isn’t tolerant to losing servers somewhat arbitrarily. How else could you ever handle hardware failures?

There is probably a niche for unreasonable customers who require 99.9+% uptime but do not want to pay for clustering and redundant servers. The best way to achieve that is to have a physical server that never gets rebooted. HW failures happen but you can explain to the customer it isn't your fault.