How is this seriously screwed up? 17-year-olds often have sex, much as we wish they wouldn't. They did in 1900, they did in 1950, 1990, and they do today. If they get pregnant, some kill the baby and then appear, to you, to be great people. If they do the right thing and keep the baby and marry (or give it up for adoption), then you call them seriously screwed up.
G-d made us all most fertile at a young age, but no longer is our life expectancy so short that we need to start having babies at 15 or 16. But once that was perfectly normal for humans.