In my experience, these kinds of things happen far more often than you hear about. Complaining is just such a carthetic experience it seems sexier to do. But in general people are mostly a decent lot. I'm frequently offered a helping hand as I go about my day. One of the curses of looking visibly disabled is that you get noticed a lot. My mom taught me long ago to thank people and reward their showing their kindness. I caught the bug and now am quick to offer a helping hand to others, usually with information. Life is a much better experience that way. (And this comes from someone who deals with pain and limited mobility daily.)
It is just much easier to show such kindness and good will in Disney World since everyone seems to have a reason to be happy. No work or school grind, just vacation. The best CMs get the guests involved with this "spreading the magic" too. Like last night at Spectro. One of the CMs started passing out Mickey stickers as "tickets". Then she recruited a volunteer from the wheelchair section, did him up with sticker banner, sticker tie, sticker hat and had him walk along the crowd handing out sticker tickets. He had a blast and everyone laughed. Helped pass the time as we waited and the weather got colder.