For fun round numbers let's say BTMRR has 2000/hr capacity... and let's say it runs 12 hours per day. That's just under 9 million riders per year. It's been open for 43 years. At some point you have to put more stock in the data than on the human nature fear of seeing a little tike ride out of the station when you say the safety restraints are outdated (over 350 million test cases, and this is just one park).
As a parent I never did hold my kids tightly on BTMRR for fear of them being jettisoned into the Rivers of America. Now, I did have many rides on Space where my hands were firmly on their shoulders