I'm not sure that the second part of your message is really "political correctness" - I suspect cynical marketing speak is at work, trying to make railway staff think of us as customers when we all know we are really passengers.

Calling even very junior staff colleagues or team members is about trying to build self-esteem but I think you're right it just devalues the words in the end. People know when they really are just drones. I wonder how the staff of John Lewis' (UK department store) feel about being called "partners" - which they always have been - although some have always been more equal than others.