It likely wouldn't be too difficult to write a script that checked two conditions: how many people are online and how long since the last reset.
If both boundary conditions were met, it could start a reset countdown.
I agree, however, that I haven't noticed the server having fewer than about 10 people ever lately...except immediately after a reset when people start logging back in.
Regarding a set time restart, I wouldn't like that to occur every day. IMO server resets are a necessary evil. It's not true, after all, that time by itself causes a server crash. Rather:
1) Crashes are a somewhat random event that gives the illusion of time as the cause; as time goes to infinity the probability of the random event occurring reaches 1. (A subtle, catastrophic bug or bugs in a piece of seldom accessed code.)
2) Crashes are attributable to gradual degradation of performance and resources, most likely due to something like a memory leak.
If case 1 is true, then periodically resetting the server does no good. The consensus, however, is that case 2 is the problem. If that is true, then we should be able to predict server crashes as performance will get worse and worse before they happen.
IMO, therefore, the suggestion that the time after a positive server reset vote be shortened makes some sense. If users believe a crash is imminent, better to reset voluntarily and quickly.
The ideal time limit is debatable. Moreover, at least by signalling a plan to reset, some players will already be saving and logging out. Those who choose to stay in to the bitter end assume greater risk, but at least it's of their own free will.
So after all that thinking out loud, my conclusion is that the status quo is fine. I'd rather spend resources figuring out what causes crashes than tweaking something that we can control because we can control it but we have no idea how much good the tweaking will do.
FWIW, I've long suspected that something with crafting contributes a lot to crashes because of the simple reason that so many times when we crash someone says they lost uber crafting effort.