It really is just a matter of scale. I've known some evil little fuckers, but they lack the resources to commit full scale atrocities. They're not employing children in hazardous conditions or selling tainted blood, but that's only because they don't have access to a steady supply of either.

The ethics is actually very simple. Taking those two examples:

Kids love to work if you just give them the chance. What kid wouldn't want to go and show how they can do grownup things and at the same time make money to help their family survive? It happens all the time with family businesses. Just because I'm a wage slave means my kids can't contribute? What kind of elitist bullshit is that?

The rest is just regulations meant to strangle the small businessman. You've got some pencil neck in an office somewhere who wants to stop LIFE SAVING MEDICATION from getting to people who need it. Bitter little fuck cares more about swinging his dick around and writing "laws" than actually helping people. Most of that blood is perfectly fine but the paperwork got fucked up and sure - maybe some isn't fine - but if you ask the guy bleeding out from a stab wound if he wants some, he'll say "YES!" In any case, malaria will probably get the poor fucker before the AIDS does. And he probably already has the HIV anyway.

/s for those last two paragraphs because it's not an argument that I'd make, but it very much is a parallel to arguments that I've seen being made in real life by seemingly normal people.

And then of course people tend to operate on a spectrum of
*literally does not care
*only cares if it's happening to me
*only cares if someone else finds out (because then I'll have to pretend I never noticed)
*cares, but not enough to lose my livelihood over it
*cares, but is really good about not thinking too hard and/or focusing on all the nice things instead of the things that probably aren't even all that bad
*will think about quitting, but realizes that they other guys are just as bad (or worse)
*will quit and go live in a cave