If you can make money from it, there will always be someone willing to do it. And/or there is always someone you can compel to do it. It sucks but you pretty much have to operate with that assumption for most things.

Yes, but if you turn down the opportunity, statistically the person who takes it will be slightly worse at their job than you would have been.

If enough people apply some ethical line, it creates a genuine headwind for evildoers.