[billyjobob]

Sure there will always be someone willing to do it. But since you got hired and they didn’t, you are presumably better at it than they would be. So if you quit for ethical reasons, your unethical replacement won’t be as good. Thus the effectiveness of the unethical company is reduced, and eventually the level of employees would fall so low the company couldn’t operate at all.

[IanSanders]

That's assuming that either moral values correlate with skill, or that poor ethical standards are rare.

[gidorah]

I guess we all make choices about the kind of work we do. If enough devs feel it's not something they can support, the co wouldn't be able to do whatever the thing is.

I am an accountant, so can and have been put in ethically dubious situations. I couldn't have known beforehand, but once I did, I chose to move on. But where the facts are apparent before, I can just choose not to do that work.

Amazon were recently hiring for finance roles near me. I chose not to apply on ethical grounds. Will they miss me? Probably not. If no one worked in finance because of ethical concerns, then they may have a problem...

[pessimizer]

It's not assuming that moral values correlate with skill, it's assuming that if skill is evenly distributed (independent of moral values) then intentional selections of the highest skill from a larger pool will tend to be better than the same from a smaller pool.

I think the real bad assumption is that the sum of individual employee skills correlates with corporate success. The larger the company, the more corruption and economies of scale swamp skill. FAANG products consistently get worse for users as time goes on, and any skill becomes focused on exploiting scale, lobbying, and holes in regulation.

Your little company with skillful employees that build up a great reputation will eventually be purchased or regulated out of existence. Skill may be enough to overcome your competitor's monopoly advantages, but the gap between what your ethics are keeping you from doing and aren't keeping your competitor from doing put you at a double disadvantage.

Even worse, giving up makes you a multi-millionaire and allows you to join the monopolist club (or just retire, if you want.) Powering on until bankruptcy makes you an Uber driver.