Simple. He knows what he's pushing is untested and unapproved.

His scientific training tells him tells him this is reckless at best and potentially murderous at worst.

He feels the pressure from every direction to either push it or suffer the consequences, which will be high, including loss of job, benefits, and approval of superiors and colleagues.

So two possibilities exist. Either he is a spineless slug, who is participating in unethical and potentially genocidal behavior, or she is "fucking stupid."

Expect him and most others to go with the self flattering alternative.

It is classic cognitive dissonance and projection. He despises his actions (inactions). And he must attack anyone who reminds him the creature he has become.

That's how people are convinced to participate in genocide.