I don't think that appealing to courtesy is really the play here.

We are discussing ideas about security in a place and manner that allows us to have honest and frank conversations.

I think security teams optimizing only for security is actually very apt analogy to cancer: Part of the organization is acting in a manner that is negatively impacting the organization at large - while positively impacting that subset of the organization.

Cancer is the act of some cells in your body prioritizing themselves at the expense of the whole.

Personally - I think you're digging to find an insult in that comment, and I take it as a way for you to disengage with the topic at large.

This is an attitude that is routinely used to shut out voices that don't match the current "dress code".

Trust me, I'm hardly going to be calling you cancer over the dinner table for not passing the salt. I'm using that word intentionally and carefully - in a frank and honest conversation. If you're feeling hurt (especially on behalf of someone else...) maybe go do something else?