Something I think that's missing in this discussion is the fact that most of this stuff doesn't actually take that long to 'teach'. For example, teaching a group the basics of GTD wouldn't take longer than about half an hour - or at least, the bits of GTD that are relevant for students.

Similarly, all the other things that have come up (money, health, sex ed) are (i) eminently teachable, and (ii) teachable in a very short space of time. I'm a British 16-year-old, and at my school one hour every Thursday afternoon for first years (13yo) is devoted to 'PSHE' (Personal, Social and Health Education). There is an organised year-long syllabus, and topics covered include everything from smoking/drugs/sex to time management, communication skills etc. I don't know how the school system works in the US, but surely it would be quite easy to institute such a requirement nationwide?

And as for all these calls for 'critical thinking' (@Alison, @Scott etc.) - isn't that the whole reason we do maths, history and so on? If you don't gain critical thinking skills from your standard school subjects, then there's something seriously wrong with your schools!