It is not that you want to sterilize anyone, more that you are willing to take discuss the theme, for example the merits/criticisms of Project Prevention.
That is just intellectual honesty and the ability to entertain thoughts in a specific context, but not everyone is able see how someone could make an argument without believing it.
If only more were able to play "devil's advocate" and mentally argue the other side. It really helps to be sure you aren't just fooling yourself, which is all too easy.
Not everyone is able to imagine how someone could discuss something without supporting it. Also why some think supporting rights of free speech for all means endorsement of all.