Depends on the repercussions. Telling the child he's been a bad boy and never to do that again is not punishment, it's giving the child the attention he wants. Parents don't really punish their kids anymore. And yes, morality is a learned behavior which allows one to make a conscious, hopefully informed, choice. And that's the point of this topic. Should young teens be allowed to make that choice for themselves? And if so, should they have the tools and information necessary to make that choice? I think they are making those choices, despite what their parents may want, which makes the first question moot. And makes the answer to the second question a resounding "YES"! The parents must provide the "tools", the moral background needed to make the choice. The schools must provide the information, the real-world biological information which they need to know. Then, if the young adults decide to engage in sexual activities, they should have the ability to obtain the condoms and birth control systems needed to keep them safe from disease and unwanted pregnancy.
Ask yourself, Why are the schools not doing their jobs? Could it be because parents won't allow them to teach their kids about "dirty, nasty" sex? Could it be because parents won't allow the schools to discipline children for misbehavior? Is it because the parents don't want their kids learning that "science stuff" that says the Earth is more than 6000 years old and that "man evolved from monkeys?"Schools are not doing their job. Based on their rate of success. How young? Is it not better to deal with the questions when the child seeks the answer than for somebody to simply decide now is the time for all children to learn about sex?
As for what the schools do is to teach way more in cultural stuff than real education, ya know readin' writin' and rithmatic. And all that history and science stuff.
In short, perhaps the schools are failing because parents are forcing them to teach only those things which they, the parents, consider "moral" instead of teaching what is right.