A thoughtful essay, I agree with its spirit. Nicely written.
The arm-waving stuff about evolution disappointed me, tho. Supposedly, the genes humans have are in aggregate woefully ill-suited for success in modernity, at least this is what I hear from people who make similar arguments relating to evolutionary psychology. Programming computers post dates by at least 100K years the environment in which our genes were supposedly selected for reproductive success. On theory, everyone of us ought to be clumsy at best around computers, tho the evidence is all to the contrary.
Even granting your evolutionary premise tho, it has some problems. For one, I think you overlook a number of notably spectacular successes in eusocial species where size matters. Instead of lions in Africa, for instance, spend some time observing an ant mound. I also wouldn't expect that reproductive success and professional success would necessarily track each other. Or maybe I misunderstood you.
My $0.02: I think fulfillment of the individual and the success of the organization is more the result of the nature and motivations of the actual individuals involved with it than, per se, the size of the organization. Personally, I've worked as a programmer for big and small, but my best experience was as a private contractor. The evolutionary equivalent of the lone hawk if you'd like. (I'm now doing something ENTIRELY different).
I think most young programmers are well advised to spend some time in the box before they can learn and appreciate thinking and working outside it.