As Ana and Wings correctly said above; reboots are sometimes requested if there are issues in-game; for example commands not working, TPS dropping unexpectedly or issues with mobs - and happen on all servers from time-to-time - not just Aether.
While I do understand, and see your point; there are supposed to be ~2 programmed daily reboots, and the others are often requested in an attempt to resolve the afore mentioned things that sometimes do unfortunately occur. These are all issues that haven’t yet been resolved/haven’t needed to be looked into, as reboots conveniently resolve them.
From players’ perspectives, I do understand how it can cause frustration... but at the same time, players will also be frustrated if things don’t work 100% correctly at all times ... so either way, the staff don’t really win.
Forced reboots just seem to be the lesser of 2 (apparent) evils.