Because I am completely torn between "But theoretical understanding of a wide variety of topics is important!" and "Nothing I was taught in school between the ages of 13 and 18 has ever been of any use to me whatsoever, and really they could have interspersed it with some things that were."
Oh, and there's an excellent follow-up video here, where he talks about the various responses he got.)
(No links yet, due to Delicious continuing to be rubbish. How hard can it be to run a database of links?)
NOTE: Please do watch the follow-up where he covers the responses he got, he covers a lot of the objections that he got (and I'm seeing) there very well.
Original post on Dreamwidth - there are comments there.