No, I know human nature. While some as I stated would accept the explanation when provided, invariably there will be some who will not accept it and while perhaps not creating a mosh pit, will nonetheless put up a stink if they think that it will get them what they want.You sound like you have some examples of when previously calm customers saw one person move to another seat and immediately went crazy with chair envy and turned the train into a moving mosh pit. Should be interesting to hear about it.It's not a matter of being indifferent. It's a matter of me-too-ism. If they let him sit there, then someone who is going all the way will want the same privilege. And they won't want to hear the explanation that he gets to sit there because he gets off before the group gets on and they don't. All they'll see is him getting special privileges.
I once watched a man walk of out the JCPenny store where I worked many years ago in his stocking feet because he backed himself into a corner and decided that getting his money back was more important than anything else. But he & his wife tried every trick in the book, including yelling and yelling at a manager that I was calling on the phone to come down to help.