I honestly don't think it's an AWOL question, but that there simply aren't enough of them, especially when the schedule is not adhered to down to the minute, which is, for all practical purposes, a daily event.

Throw in a mechanical or bad weather and it just snowballs to the point of waiting on the tarmac for an hour (or more) just for an agent/groud crew to become available to service the aircraft's arrival.

AA has cut staffing levels down to the absolute bare minimum and this is one of the consequences.