is it not disrespectful to talk about this material in this way?

That's exactly the idea: to either shock into not wanting to touch the conversation at all, or to browbeat anyone who calls bullshit with "it's disgusting you would ask for any proof of such a sensational claim" -- burden shifting, essentially. It's much the same logic behind inventing genocides every enemy of the U.S. is supposedly doing, then getting indignant and attacking anyone who asks for proof.