Perhaps I'm of the wrong mindset but I've believed the recent server stability issues are caused from an overpopulation in Ul'dah. One way to reduce that population would be to force players to log out after 30 minutes of inactivity.

Some may argue that this will prevent people from selling things in the Bazaar, but I'd love to hear about people who do not shout and actively sell things in the Bazaar. [I empathize with you who are not able to be in the Ul'dan market wards.]

Other than that idling in Ul'dah servers few other functions:
Holding hands with linkshell members in designated linkshell hand-holding spots.
using up additional electricity with the high resource use of FFXIV.
remaining in active stance because you think your weapon or armor is neat and you want everyone else to experience the neatness.

Losing these "functions" would certainly be worth additional server stability, if it were a major cause of instability, yes?