I'm sure that is what you have been taught and have even read in skewed and flawed accounts of history.
It's a phenomenon as old as recorded history. You can go back to Old Testament times to read of a people who had all their needs provided by the work of their hands and a benevolent God--that is how they saw it--but still thought their lives would be easier and better if they had a king to manage everything and make everybody behave as they should. The motif is repeated again and again: "And there was no king in Israel and everyone did what was right in their own eyes." So the people clamored for a king. And it didn't solve their problems.
The Founders gave us the first nation since Biblical times that has no king or authoritarian government that assigns what rights the people will have. And for the first roughly hundreda and fifty years or so we had the most free, most generous, most innovative, most creative, most prosperous people the world had ever known.
But still there are those who "clamor for a king" who will manage society, assign the rights, obligations, and responsibilities that the people will have, and think that will somehow make our lives better.
It won't.
I'll put it this way. My understanding of history is a lot less Amerocentric.
Well, I was not entirely responsive to your thesis which was:
"I find it odd that anyone who believes that most people would be happy with a rather low income as long as it's "comfy" would also support a highly free market economy."
I believe your thesis is flawed in that most people are NOT happy with a rather low income despite being 'comfy' but a percentage of folks always have been happy with that and probably always will.
The problem comes with those who aren't happy with their rather low income who do not look to themselves to remedy that but rather look to somebody else; i.e. the government, or the 'rich', or the system or whatever to remedy that.
Those are the ones who clamor for a 'king' to save them from their plight.
Those who love freedom don't expect others to provide for them but expect to do what they have to do to provide for themselves.
It's all in the social psyche. Some value individual liberty. And some value the herd mentality.
I beliee Americans overall are probably less inclined to appreciate a 'herd mentality' than are many Europeans, Africans, and Asians.