Bamspeedy
CheeseBob
It's sheer force of habit; when you're required to say this all day long, you end up saying this even if it isn't exactly necessary. I work customer service in a call centre, and after a day at work I once ended a phone call with my dad with "Do you have any further questions at this point ?".

After working a shift at one place I go work at the other job and pick up the phone and say "Thanks for calling..." and said the name of the other place I worked at.
After saying "Thank you" 500 times a day I wouldn't have any enthusiasm in it at all anymore, so I would sound like a robot.