Because for many, XIV is as much a chat client as it is a game?

An FFXI style configurable auto disconnect would make sense but fixing the queue system would make far more sense. I can only assume that it's hosted on the same cluster that handles exchanging characters between the various zone and duty servers (The weak link that by my reckoning, caused all the early access failures and character lockouts in P4), hence why it's been dialled down to near nothing.

Please try to remember that not once has in-zone performance been an issue even in Ul'dah where the idle players are at their highest ratio.