I agree with safety..and don't think that just missing a height..I mean just missing-like directly below the line, is at all putting a child in danger. Especially when similar rides have lower height requirements at other parks. Also, because I grew up on said rides, without harnesses, only lap bars back then, and we were all fine.
Car seats however- totally different ballgame. My son was rear facing until 2 and a half. And is still in an actual car seat after just turning 6. He will remain there until probably just before 1st grade. Car accidents are not comparable to the low restriction on child restraints when I was younger. We didn't have people texting back then...etc.