Nope, I'm not disagreeing with you!! I don't think the driver was correct in what he said, much less how it was said. There is never any excuse for rudeness, and that comment was rude. Were you wrong? It depends. As I said before, tipping should never be expected!!! That's a bad mentality to have. Tipping is always up to the customer. I expect to be treated with civility with no regard to whether I was tipping or not...period.
Here's the thing....there are going to be many people that wouldn't have given a second thought to that driver's remark. They may have thought the driver was crazy polite and nice. They would not have realized that a tip was expected. So they would have had an entirely different take on that rude comment. You, on the other hand, knew you should have tipped. So you realized what the comment meant. And of course you are peeved.
I don't think there is ever any excuse for that kind of comment/attitude from anyone. I don't care if it's at WDW or in Boston! If I got that kind of remark, I'm sure I would have said something in return...or just possibly just taken out my pen/paper (that I always have with me), looked closely at his name tag, written the info down, then looked at the bus number and written that down, along with the time...then turned to the driver and said 'Thanks for the wonderful attitude.' and walked away. Perhaps that would have been the wake-up call he needed.
So, no, I don't disagree with you on the comment.