Here's why you should hire me . . .
This is a real multi-prong question. They might be setting you up to to determine if you are the type to diss colleagues and co-workers. At the same time they are giving you one more chance to sell yourself and want to see if you'll seize it. Don't fall for the bait of the former, but use it as a positive while taking every opportunity to play yourself up to the hilt for the latter.
You can say something like, "I know you have plenty of excellent applicants who are interviewing with you today. You wouldn't have taken the time to bring us in if you did not feel we could contribute to your company. I've spoken with some of them and they are all friendly people that I, for one, would enjoy working with."
"Here's why you should hire me . . . ." and summarize your background, skills and accomplishments. Give examples and/or documentation of each, e.g., "I trained at Mom & Pop's FBO. I earned money for my training by bagging groceries at Safeway after school and by sweeping floors at the FBO on weekends. Mom & Pop hired me to instruct, and later worked me into 135 charters in their KingAir. I was eventually designated as Chief Pilot on their operating certificate. I left there to fly night freight as a DC-3 FO for Classic Air Freight in Ypsilanti. I eventually upgraded to Captain and become a check airman. I helped to create new training materials and was named Employee of the Month for my contributions. I am sure that, with time, I can make similar contributions to your airline." Etc.
That's something like how I would answer the question. Some questions are minefields, but many others are further opportunities to sell yourself.
Hope that helps. Good luck with your interview.