A flight into DFW last year had a REALLLY lengthy delay getting the jet bridge up to the plane.

I was 'happy' that my connecting flight was leaving only ONE gate away so not in a 'rush'.....

Well, one tire on the jet bridge had gone flat since the aricraft previously using the gate had departed. They could NOT move the jet bridge with the flat tire! They tried to get it pumped up (20 minutes).

Eventually they brought up boarding stairs and we all deplaned (or were going to) thru 3L (757) .. much of coach exited that way and made their way across the ramp area .. FINALLY they got the jet bridge moving but could not get it perfectly aligned to the plane and left about a 1foot gap between 1L and the jet bridge. We in First were 'assisted' off the plane ...

Rushed to my connecting gate as final boarding was taking place. My wonderful 'next gate' connection almost was lost due to jet bridge flat tire!

I think the OP needs to look at the scheduled arrival time vs the actual arrival at gate time. Yes, many times even short flights (let alone transcon) will arrive 15 minutes or more early. And there is NO ONE there to accept the plane (either the Gate Agent to move the jet bridge or MANY times the ground crew that guides the plane in are not even there for 5+ minutes).

AA is running their staff VERY VERY tight on schedules ... and there really are no spare staff to manage an early arriving plane. Its a fact of life now days .. cutting costs to the bone.