I appreciate it when gate agents assign me an exit row, but I certainly don't expect it - especially when paying customers might be able to sit there instead. That's why when jumping on SWA (or any carrier with open seating), I'll head to the back of the airplane and let the pax get settled, and only then if I see a better seat I'll get up and move.

The way I see it I'm a guest in your house, so I'll make sure your bread and butter are taken care of before I start considering my own comfort.

That said, I also think an FA laying into a pilot in front of passengers is a toolish thing to do. I had a JetBlue gate agent do that to me once (onboard the airplane before we pushed) - not cool at all.