I like that Roy got to have fun with the curtain call and, with the fun they were having in the dugout, it was like the players were letting the fans be a part of it by getting Roy to walk up the steps. In just about every way, it was a positive thing. You are right, the fans got to show some appreciation for Oswalt that they usually don't get a chance to do.
That said, I still don't like curtain calls.