For starters, the FO was a 'tard who should have professionally voiced his complaints; he obviously never worked as an airline agent. Besides, AWAC pilots can send a delay code to dispatch saying that they were late because they weren't given access to the airplane...the delay wouldn't be on them anyway.
On the other hand, when I flew for AWAC I too had occasion to wait a long time at the gate after an early show, only for rampers to show up and get ****y at *us* because there was going to be a delay. As a flight crew member, I'm trained to go to the gate when I clear security to get access to the airplane for preflight, and if I can't get access to the airplane then obviously that causes problems. In those situations, I too have been known to be a little cranky if I haven't had my coffee...but I didn't unload on an agent who quite obviously was busting their ass and doing the best they could do.
A little understanding and professional courtesy between flight crews and agents goes a LONG way in serving the passengers...and THAT ultimately is everybody's job in the airline business.