Let's say facebook sells customer data and eats babies, and you're opposed to both of those things. You come to the conclusion that you can outcompete facebook without eating babies, but only if you're willing to sell customer data in the same way facebook currently does. You're trying to replace the incumbent so that less babies are eaten (or certain speech isn't censored, or certain speech is censored, or <insert any ethical cause besides the one you're compromising on>). It's that when you hold more than one value, they are sometimes at odds. If you try to be the most ethical in every regard you'll most likely be outcompeted, in which case you won't even be making an improvement in the current state of unethical behavior. Even finding tradeoffs that improve average ethics while also being competitive is difficult, since others are playing the same game without your ethical objections to certain practices.

Some people choose to pull the lever in the trolley problem.

Possible, but it can also be that you don't have a better business idea and can't get work anywhere else.

Getting a job as a developer can be tough in 5% of the circumstances. I've read a quite recent account of one, and don't forget that the founder of WhatsApp had a similar situation.

All I know is that people don't respond well when they feel backed in a corner.

There are so many reasons that in a few cases are true, but anyways, this is one of them. And if you think they don't exist, I'm pretty sure they do.