I just think it's pretty sad when a pilot, regardless of who they fly for, doesn't have the common courtesy to say hello or acknowledge the other pilot. Last week in LAX, my FO and I were walking down a very narrow corridor and a UAL pilot was walking in the opposite direction. It was impossible for them to not see us as they had to move to the side as we passed...... I said "hello United Captain" as they passed. I stopped and turned around to see their reaction. They stopped, looked at me, and gave me a "go to hell" look. Wow....very "unifying" and professional. So, who is the enemy here? Hurt my feelings? Nope, just think it's a strange way of supporting each other since we ARE on the same team, believe it or not.