It survived fine - but many, many, many 14- to 17-year olds gave birth every year. Since we've decided that is officially a Bad Thing and passed laws trying to prevent it, it shouldn't be surprising to see this kind of recommendation from an official body of physicians.
I don’t see people being locked up for knocking up unwed mothers these days.
Administrators and physicians are encouraging children to sexually experiment these days (even with BDSM, choking, “safe words”, genderplay, homosexuality, etc.).
THAT used to be called “corrupting a minor”. Today it is the “Establishment”.