I really don't think it's worth it getting mad at people like this... for one thing, there are many things that could incapacitate a 40-year old that forces them to use a scooter. You really never know what a person's individual circumstance is. But even if they were abusing the system, it's their problem and not ours. If someone wants to be a jerk, I let them and don't let it bother me. There are some MAJOR jerks out there and they will ruin your vacation... if you let them.
Society is changing, yes, and people's spheres of awareness are closing up tighter than ever before, but it doesn't make them "bad" people. But one time I did run into a situation that was truly horrible, it was waiting in line at the Orange Stinger at DCA years ago. I was patiently waiting in line with my family and we had a rather large party. While the line was moving this group of kids decided to cut in line right between me and my family and we were cut off by the idiot CM working the line. I explained the situation, but he wouldn't let us go and family had to wait for the 2 of us that didn't make it due to the line jumpers. I was pissed... these people had no excuse other than truly being bad people. And they took away a serious part of the experience by bumping us off the same ride as the family... not to mention the CM was dumber than a box of rocks. These were not just people not aware of their surroundings, these are people who truly destroy the Disney experience.
The Disney CM has an undeserved reputation of being the best in the industry. There are truly some gems here and there, but overall I feel that the employees at Knott's Berry Farm are MUCH better... they play around a lot, they are always friendly and courteous, the performers in costume are genuinely funny, and I've never had a bad experience there. A lot of CMs at Disneyland just appear to be going through the motions to gain a paycheck and I've had a couple bad experiences there. I know I don't speak for *every* one of the CMs working there, but that's just the overall vibe I get nowadays.
As for not bringing a credit card for security, it's actually much more dangerous to bring cash as far as security goes. Cash cannot be replaced and if it is spent by someone else, it's gone for good. With a credit card you can cancel it right after you find it missing and you won't be responsible for any charges. I carry only emergency cash and use my credit card for everything. It's by far the most secure way to spend money. But I totally understand why you didn't bring it for overspending purposes, that is quite admirable and commendable.