[Suicide Junkie]

For example there was a recent thread on Usenet about some biology professor would would not allow students to graduate unless they asserted that they 'believed in' evolution.

That prof could use a smack upside the head

Requiring a real understanding of it is certainly not a problem. Without learning the strengths and weaknesses of the current theories, what chance do you have of improving things?

I'm not a chemistry major, but I'm sure there must have been some good uses for the phlogiston theory. Chemical reactions are what it is good for, rather than mechanical things. ISTM that "Phlogiston concentration" would relate to the degree of oxidation.
It was not correct, but it was not totally wrong in a practical sense.