To use a trolley problem metaphor, what they are saying is not pulling the lever is the same as allowing five people to die. If fascism is progressing and you do not stop it, you are allowing it to progress. Whether you consider that propagation comes down to your ethical framework, but from a consequentialist view it is accurate
Except carcinnisation only happens in some crustaceans, so it’s less a universal thing and more a selective pressure