were these scientists debunking or refuting ... or revising ... a theory?
I think you've put your finger on it, W'ON. "Bunk" is not science. It doesn't even masquerade as serious science. It appeals only to the gullible and the credulous.

Scientists do not "debunk" theories they disagree with, as you have explained so cogently. They respect the mind and the intellectual process which produced the theory even if they disagree with it.

"Bunk" can never enjoy this kind of respect. It is, after all, just "bunk". If follows that it is far easier to debunk bunk than it is to refute science.