I'd say that all of them are arseholes. The ones running the scams are not the local poor - they are poor relative to us in the west, but not in local economy they are relatively powerful. They are the local criminal hot-shots.
>but often the people on the ground are just human beings who have no other way to earn money
This is the problem. The above people use the poor(er) in their area as cannon fodder. When a 419eater story shows someone in a massively embarrassing situation that is not the scammer, it is some local fool that the scammer has somehow scammed (or forced) into playing the game. Yes they have wasted the scammer's time, but that is not the scammer being humiliated in those pictures.
So the bot is probably a better idea than targeted humiliation. Making crime quietly unprofitable is a good thing.
(You can help with Nigerian development, eg by giving to Doctors without Borders or other approaches.)
Outbound call centers employ these people by the legions.
And selling crap stock to retirees is no better than pretending you're a Nigerian prince.
I would actually consider it racist to assume that people from a certain country are incapable of telling right from wrong in earning a livelihood. India, for example, has (surprisingly) a far smaller GDP per capita than Nigeria, and despite India having a reputation for being an IT hub, one seldom hears about online scams being perpetrated by Indians. The same goes for many other poor countries whose citizens don't resort to online scamming.
Humiliating other humans beings for enjoyment isn't a great trait to encourage.
These sites are also, whether that say they 'aren't' or not, are racist on some level.
I'm sure there are some real a@#holes participating and running these scams but often the people on the ground are just human beings who have no other way to earn money.