The opposition to capitalism have such a disastrous track record, economically and in terms of body count, that embracing capitalism is far more sensible.
I'm not saying that the other systems, by which I assume you mean the various marxist political projects, are good (and we won't even get into how many of those alternatives were actually not-capitalism) but I think to dismiss the "body count" of capitalism while simultaneously ascribing all deaths under those alternative systems as the direct result of {otherSystem} is extremely disingenuous. Doubly so given that modern first-world capitalism often outsources the human cost of it's milieu to the third world so that middle-class suburbanites don't have to see real price of their mass-produced lifestyles.
Modern Western countries mostly drifted towards a mix of capitalism and social democracy.
"modern first-world capitalism often outsources the human cost of it's milieu to the third world"
This is a bit of "damned if you do, damned if you don't".
If you don't do any business with poorer countries, you can be called a heartless isolationist who does not want to share any wealth and only hoards his money himself.
If you do business with poorer countries, but let them determine their own internal standards, you will be accused of outsourcing unpleasant features of capitalism out of your sight.
If you do business with poorer countries and simultaneously demand that they respect your standards in ecology, human rights etc., you will be accused of ideological imperialism and making impossible demands that a poorer country cannot realistically meet.
The alternative systems were just as willing to plunder their satellite states and the third world IIRC as the capitalists were so it would be an equal demerit for both, I'd think?
