But they're not advocating. They're claiming they can do nothing. Quitting in protest would be more advocation.

Who says they're not advocating? Who says they were aware of this before today?

Extend this to other disciplines - if everyone who cared about security resigned every time leadership pushed to rush something out without proper testing, the world would be a worse place. Sticking around and continuing to try to change the culture is how good companies are made.