Quitting in protest is overrated. It assumes a level of economic stability only available to the very wealthy. If you have a family to provide for and you live in SF, you ain't quitting nothing. Remember, quitters don't even get unemployment.
That would be "quitting in protest without that costing you anything special".
As for "quitting in protest" period, well, tons of people have quit in protest and risked their "food on the table" for ethical reasons...
Heck, tons of people have risked their lives (and even repercussions against their family), and quit or refused to do things they were ordered to for ethical reasons.
It doesn't take financial stability to do so -- just having a spine.
And here we're talking about sought after engineers at a major company (that can always get another job), and that already make cool 100,000+ a year and most have some savings in the bank.
It should be even easier for them to step down than to some poor guy with 3 kids and hand-to-mouth wages - that might even be blacklisted. And yet many people did the right thing under those circumstances.
If we were talking about Walmart sales associates, I'd have more sympathy for your points.
Sometimes (not always) it's better to try effecting change from the inside.