You may not want to acknowedge it, but there are credentialed scientists who believe in I.D. They are a minority to be sure. Even the article acknowledges that there are many scientists who believe in guided evolution. But again that's not permitted in the schools at this time. But there are a lot more scientists who believe in I.D. than those that are willing to be vocal about it, because of the prevailing bias in scientific circles against I.D..
"You realize, of course, that this would require devoting a significant portion of history curricula to various popular conspiracy theories, physics curricula to various common misunderstandings, etc. etc. etc.?"
You mean grade school kids would be taught the original teaching that Thanksgiving was to give thanks to the Lord in addition to the now politically correct thanks to the Indians revisionist history? Or that Muslims were actually the ones that sacked and burned western libraries before they "saved western civiliation" by keeping some of the books?
I don't it would require every crackpot theory to be taught, because frankly most crackpot theories never gather much of a following.