I completely agree, it's not right - although I avoid 'unacceptable' since my only option other than accept it is give up UO, and that's unlikely
It certainly should not happen - there are bigger games out there, with larger numbers of, and probably more complex, server clusters running them, but UO seems to have more system problems than all it's competitors added together.
But.... I remember what UO customer support on these sort of issues used to be, and believe me, compared to those days this is a flood of information. Could be better, certainly, but it is slowly getting better.
So many things are still woefully poor - my contenders for worst being in-game support, enforcement of the ToS (gibberish though it may be, if it's there it should at least be adhered to!), and inconsistent GM actions - but I've not reached the tipping point on their handling of this 'situation', sad though it is for players to experience.