I think Heinlein's overlooking that are also two other complementary types of people: Those who prefer to go it alone and make their own decisions, and those who prefer the comfort of letting others make their decisions; the kind of people who find instinctive comfort in knowing their place in the primate hierarchy.

The uncomfortable truth is that a significant percentage of humans are happier with a minimum of freedom. Look inside any democracy, and you find people still instinctively and voluntarily organizing themselves into groups that minimize their individuality, like religions and political parties and social organizations and sports teams and on and on. Being in a group makes us happy.

The more I learn about primate behavior, the more pathological, if you'll forgive the overly-technical choice of words, I find the notion of the "rugged individualist". The core of human society and civilization is a group: families, and groups of families forming tribes, groups of tribes forming clans, etc....groups scaling all the way up to nations. Individualists are abberrations, usually outcasts from the tribe, and suffer in the absence of their normal social network. To be alone is punishment. Solitary confinement is considered a harsher punishment than imprisonment with other inmates. Hermits and castaways go crazy. Ted Kaczinski had to retreat to a cabin in the wilderness to sustain his insanity.

Or you could look at all of human history, and ask what individuals have accomplished all alone. I don't mean strong leaders, because obviously their success was based entirely on their ability to wield the power of a group. No great leader is an individualist, and I'd say that the opposite is true: A great leader is a social virtuoso, by definition. That extends outside of government to business as well; it's any organization.

To return to primatology and first principles: Our intelligence didn't evolve in individuals, it evolved through the interaction of groups of individuals and was a self-reinforcing group phenomenon. There's no cultural continuity to build upon without a group; no progress without a group; just reinventing the obsidian blade forever and ever until the end of time.

Minds would never have developed in the first place in an individualistic vacuum.

We got where we are through cooperation far more than competition. I'd say our most profound gift is organizational, even more than tool-making or speech, because it leverages and multiplies everything else we do.