I agree with much of what you say. Most entertaining to me is that I'm the one who used to post such things on HN. It's amazing how quickly the pendulum has swung from extreme libertarian to progressive left.
Personally, I think any ideology is dangerous. The "free market" should be a tool - good at some things, bad at others - and not an ideological dogma. I don't think it works well when enterprises cannot fail, a necessary part of the free market; so public safety, health care, basic utilities (e.g. water), etc. aren't good problems on which to apply the free market tool. It's also not useful for goods that shouldn't be distributed based on ability to pay, such as basic infrastructure (roads, phone, Internet), education, basic nutrition or health care.
But it is an excellent tool for many purposes, and has a moral basis - it provides for the liberty of the business owners to do what they want with their property. I didn't agree when it was a dogma, and I don't agree that it's unimportant. It's essential.
> Globalisation was just another means to promote economic interests. It was nothing to do with some free market ideal
I strongly disagree. Free trade is a fundamental of free market economics, in theory and reality. It's just interference in the free market, this time at an international border instead of inside it (consider: would it be different if it happened at U.S. state borders? Urban borders?). If I'm making cars and must pay more for worse steel, simply because the worse steel plant is in one location and the better one in another, that wastes economic resources: It wastes the car manufacturer's money, which could go to something more useful such as more jobs, better cars, or payments to shareholders; it wastes the car buyer's money, which could have purchased a better car (i.e., with better steel); it wastes much of the resources put into the inferior steel plant, which could go to more productive uses (look up comparative advantage); and it deprives a productive enterprise, the better steel plant, of resources that it fairly won on merit in the marketplace. The fact is that the better steel plant uses the money more efficiently, freeing up for better uses the extra money that would be consumed making bad steel and funding the people who built the better mousetrap. You probably want your mousetrap to succeed on its merits, not on whether the President happens to like you.
But there is a serious issue with the free market's (including free trade's) impact on labor. My way of looking at it is that capital can move much more quickly than labor: A factory can move much more quickly than its workers can (either to the new factory or to equivalent jobs). The economy is there to serve people, so that should be addressed.
> The US government, and most governments around the world, have been heavily interventionist since at least WWII. This was born of necessity - the Great Depression was largely the outcome of capitalism left unchecked. After WWII the U.S. economy was in tatters. Truman and Eisenhower both took very aggressive interventionist policies to keep the economy afloat.
While I agree with much of your point, parts of that history are time-shifted. The Great Depression began in 1929 and FDR took office in 1933. That's (roughly) when the heavy intervention began, and it took place until the end of WWII (1945) - though much of the intervention during WWII was for a different reason, to use the nation's economic resources for war materials. Post-WWII (though maybe not the next day) the U.S. economy was robust. The 1950s, including under Eisenhower, were possibly the greatest economic boom in U.S. history, and it continued until roughly the 1970s. Heavy regulation, intervention and taxes - though not at the scale of the Great Depression - which continued until the early 1980s, was not due to economic necessity, but possibly due to a belief in democratic government.