Your friends probably aren't engaging in "greed is good" themselves, just responding to the economic conditions created by people who are engaging in it.
In the American cultural headspace, "greed is good" refers to a very specific brand of robber-baron capitalism. It's a doctrine that was first given academic legitimacy by the University of Chicago's school of economics, then put into practice in the 1980s under the Reagan administration, and nowadays its loudest proponents are Musk and Thiel. It's an economic theory that lionizes extractive behavior by the economic elite, with some bullshit trickle-down argument that's too convoluted to be worth explaining here.
It creates an environment where everyone had to do evil shit just to put a roof over their heads, a self-regulating race to the bottom. Your friends are likely just unwilling participants, a side effect of "greed is good" rather than doers of it.
It does not. It refers to the Eighties brand of corporate raiders and excess Capitalism. It's a quote from the film, "Wall Street". That whole paragraph is wrongly conflating ideas.
Quote from my own comment:
> put into practice in the 1980s under the Reagan administration
Are you contesting the name "greed is good" because it was coined after the underlying theory was crafted? If so, I disagree. We didn't have the word "smartphone" until after those existed. The word "Christianity" wasn't invented while Jesus was alive. Trees existed before we named them.
Reagan didn't just pull a new breed of economic policy out of his ass in January of 1981. The Chicago School is informative of neocon economic policy, and once you get past the pictures of frogs, not much has changed about the modern conservative economic platform.
Yes, which is why I said "Everyone I know in EU is trying to cash in as much as they can while the going is still good".