There have been all sorts of very different societies, so appealing to "evolution" to justify any particular one doesn't really fly.
Firstly, I wasn't treating economics and society as synonymous. Secondly, it depends why a given system evolved. Capitalism's predecessors, feudalism and mercantilism, fell by the wayside through economic necessity. Its main rival in the 20th century, "state capitalism", went bust. The mixed-economy could go either way; it's too early to tell.
The American constitution wasn't dreamt up: it was common law precedent codified. Certain amendments are nicked word-for-word from earlier documents. (Notably the Eighth Amendment, pinched from the Bill of Rights Act 1689.) That's why it's so good, and why it's inherently different from idealistic enterprises such as the Declaration of the Rights of Man.
Intellectual evolution can be good and bad (I'm no Richard "
zeitgeist" Dawkins), but pragmatism is always best. Capitalism, for all its many flaws, is pragmatic, and goes seriously wrong when it's treated as an abstract imperative.
You haven't thought this through have you? You're claiming that entrepeneurship is "instinctive". You're also claiming that I've said "capitalism is abstract" - I haven't said anything of the sort. Please do me the courtesy of reading my posts accurately!
Right back at ya.

I said
some people are instinctive entrepreneurs, not that entrepreneurship is everyone's natural state. As for the second one …
Capitalism is a product of a certain set of social relations.
This is so vague it's meaningless. If "social relations" are determinative, then how did relations conducive to capitalism begin? What role do you assign human agency in engineering relations? Where's the chicken? People's motives have a spectrum of inspiration: it's not "abstract individualism" to argue that on occasion they're inspired by ideas. (I suspect you'll say that ideas are "formed by social relations", but again, I'm happy to be surprised.)
You've singularly failed to explain what causes the social relations you dislike, and how they're to be consensually eliminated. Capitalism began under a different system, and dominates the economic sphere because it's more effective than past and current opposition. Maybe a better system will come along and replace it: if libertarian socialism can't begin until capitalism is gone, then it never will.
Or put it like this: did the first shareholders in the Dutch East India Company say, "There's no point trying capitalism until we get rid of mercantilism"?