No chance your father or your joiner friend hadn't seen those ads of the saws which automatically stop on contact. But they chose not to buy one, because they decided they didn't need one. They had that choice. Or if before those existed, to use a hand saw.
Regulation is nothing more than saying "we're superior to you in making choices for you, so we'll do so". And it's made not by efficient innovative geniuses, but by the same people who run the DMV. And it's not imposed on children by parents, it's on grown adults by other grown adults with no legal accountability. And it ossifies technology by locking in certain measures which will quickly drift out of date. And, as we've seen with the FDA and Opioids, it gives a get out of jail free card to wrongdoers who game the rules, because they can point to their compliance and say "so look, we followed the rules, we shouldn't be liable".
It's just unbelievable people think regulation is in any way a good thing.