Earlier this year I exchanged some e-mails with an Anthropology professor at the University of Toronto who blames some of the ills of the world on Capitalism. Bogus, just a way of transitioning blame from greedy assholes to some ideological concept.
Humans are sociobiological animals. A guy named E.O. Wilson developed his theories on sociobiology while studying insects and then applied that theory to mammals, including primates, humans.
Many mammals exist in social groups with a rather flat hierarchy where an "alpha" pair controls the most desirable resources, generally some kind of food. The communities tend be very small and all of the members interact together.
Humans form smaller communities, churches, families, businesses, villages, etc, and as those communities grow and grow the social hierarchies become more and more rigid and more and more stratified.
Capitalism is a way for us to continue that sociobiological need for social hierarchy where "alpha" members accumulate the most desirable resources. In some communities those resources are skills, mental or physical, power or charisma, the ability to convince others to do what one wants, knowledge, memory. The lowest common denominator is money and that ends up being the most desirable resource among the largest portion of the community.
Money often follows charisma, not always, but often.
So, capitalism exists as the primary economic system because it allows humans to support their sociobiological predisposition to establish social hierarchies where alpha members can accumulate desirable resources.
We would need to have a different "lowest common denominator" to establish a different economic/sociobiological social hierarchy based on something other than capitalism.