When I used to commute down to SFO/SJC regularly, I used to love that I could time things to walk in right before the door closed and not have to get up quite so painfully early.

But having been on AS a bunch recently, I can see what they are doing and why they want to encourage everyone getting to the gate early. Last night I flew SNA-SEA and when I looked at the scheduled operation on the way to the airport it reported on time departure but late arrival due to strong headwinds. Of course the equipment arrived early due to tail winds, and to keep their schedule intact, they announced they were going to get us out nearly 20 minutes early. They did just that and I appreciated getting home on time, even a few minutes earlier than scheduled.

That's just one example, but more than any other US carrier, AS seems to be dispensing with scheduled departure time and trying to push back as earlier as they can.