I'm in favor of the height restrictions and I appreciate castmembers following procedure to ensure my child's safety.
However, I wish there were a better system for checking height.
On our last trip, DD was just at 40". Whenever we wanted to ride something with a height requirement of 40", DD was measured at the beginning of the queue. As we got closer to the front of the line, invariably she would get pulled out of the line to be measured again. DD took it in stride, but it was a pain to squeeze by people to have her height checked yet again.
I was thinking it would be nice if children were measured at the park entrance and given a wristband to show what height requirement they meet. The different heights could be represented by different colored bands. Then, in theory, kids would only have to be measured once. Signs at the height-restricted rides could exhibit the appropriate colors (coordinating with the wristbands). Parents would see the sign color and have a chance to steer their kids away from rides for which they're too small, and maybe avoid disappointment.
LOL! Can you tell I've given this some thought?

Maybe I'm way off base -- I'm sure someone can point out holes in my plan -- but it sounds good to me and it seems as if it would make things simpler.
OP, thank you for sticking to your guns to keep children safe, despite the idiot parents.