"Teach the [deliberately contrived] Controversy" has a long and sordid history as the chief dialectical dodge employed by the rabid, reactionary Christionists who find themselves simply sidestepped and bypassed by a secular world with better and more productive things to think about than discredited, Single Spook Animism. The disruptive tactic persists, however, because as Justice Oliver Wendell Holmes put it long ago:

"Controversy equalizes wise men and fools alike -- and the fools know it."

There you have the short answer to those fools who think they can disrupt any conversation as a means of covering for the fact that they have nothing of value to contribute to it. For the longer, more complete answer, see John Dewey almost a century ago:

"Old ideas give way slowly; for they are more than abstract logical forms and categories. They are habits, predispositions, deeply ingrained attitudes of aversion and preference. Moreover, the conviction persists – thought history shows it to be a hallucination – that all the questions that the human mind has asked are questions that can be answered in terms of the alternatives that the questions themselves present. But in fact intellectual progress usually occurs through sheer abandonment of questions together with both of the alternatives they assume – an abandonment that results from their decreasing vitality and a change of urgent interest. We do not solve them: we get over them. Old questions are solved by disappearing, evaporating, while new questions corresponding to the changed attitude of endeavor and preference take their place. Doubtless the greatest dissolvent in contemporary thought of old questions, the greatest precipitant of new methods, new intentions, new problems, is the one effected by the scientific revolution that found its climax in the ‘Origin of Species.’”

John Dewey, The Influence of Darwin on Philosophy (1910; reprint Bloomington: Indiana University Press, 1965), page 19.

Americans do learn slowly, sometimes; although for the most part they seem either uninterested in learning or else just violently opposed to learning anything at all. And what better avatar of atavistic anti-intellectualism than that shallow symbol of the simplistic: the goofy girl governor of ass-backwards Alaska?

I'm in favor. I belong to the Flat Earth Society and our students are woefully uninformed about that controversy as well. And how about that "Law" of gravity?

There's a "controversy" because Christianist pastors (and Christianist-funded scientists who publish their work in non-peer-reviewed journals) say there is.