It doesn't matter if the tape measure says you are 100' tall. If you don't measure to their sticks you don't ride. I'm fine with that. Its a safety issue. I get that. When my daughter didn't measure up nobody argued, threw a fit, or anything else. We said thank you, pulled my daughter aside, explained it to her (she understood, no problems) and moved on to the next thing.
The point is that they are not accurate. In our case it was at least 2" off on Indy. Again, that's fine, but the problem is that the sticks are not accurate even amongst themselves. She also barely scraped by on Space Mountain (40") (by about a paper thickness) but was a good half inch over the stick at Tower of Terror (also 40"). Its kind of confusing and not very reassuring. The whole idea is safety. So if the height requirement is 40", shouldn't that be the same at both places? Oh, and btw, both rides were the first ride of the day, same shoes, no hat, and she stood as tall as she could both times.
Seriously, at the end of the day these are RIDES. It isn't the end of the world is someone doesn't get to ride (or at least it shouldn't be) and in a lot of cases (not all of course) the child will only get as upset as the parents. Why get upset about not being able to ride one ride when there are so many other fun things to do. That said, it is a bit confusing and irritating on occasion.
Somewhat off-topic. Dinosaur at AK is 40". Indy is 46". Why the big difference? The ride platform is the same and I could swear the vehicles are the same.