You name child labour as an evil thing. That's a great example of something that could potentially be made even worse if you just tell people to stop doing that evil thing without doing anything about the reason people do the evil thing.
It's true that behaviours can reinforce themselves. "Machismo" could easily be a thing where you are forced to play that game because so many others play that game, and that we could all be better off if we managed to coordinate a break with those practices. I said customs can be sticky.
When I said make sure the tigers are gone, I meant just that. Maybe the tigers ARE gone, and this is just our process of unsticking our bad customs. I just don't want us to take the easy way of assuming we are inherently better than earlier generations/other cultures.