Originally Posted by DudeE

Another annoying aspect of this practice is that they're not about to hold the door for those late passengers. So while everyone on the arriving flight can endure the inconvenience, the door will close on the departing flight right on schedule (or even earlier in my experience) whether or not those passengers make it to the gate. I have (more than once) arrived on a tight connection - along with a half dozen other connecting passengers - to find the gate agents had closed the door on us and refused to reopen it.