I think it’s a legacy of Cold War propaganda and McCarthyism.
It’s also an association that has no historical, empirical, or philosophical validity. Without even having to go into why capitalism has nothing to do with freedom, there are glaring examples of capitalist countries that are actually very authoritarian: Pinochet’s Chile, modern China, Singapore, and many others.
In recent years, the capitalist argument has evolved through the likes of Friedman (as mentioned earlier) and other hyper-capitalist “thinkers” like Rand, Hayek, von Mises —and spawned an entire industry of free-market think tanks, self-styled philosophers and capitalist apologetics, and the entire “Libertarian” movement.
In the newly evolved conception of capitalism, capitalism is freedom because actually existing capitalism is really “corporatism” and “crony capitalism”—but really real capitalism is just people entering voluntarily into contracts and making uncoerced mutually beneficial exchanges.
If it weren’t for pesky regulations, and the government doing favours for capitalists who buy favours from them, or any other sort of market interference or anti-competitive action by capitalists or others (like those nasty trade unions)—we’d all have true capitalism™ and this idealised capitalism would perfectly allocate resources and result in perfect equilibrium as the invisible hand of the market does its miraculous work.
@SecondHandStoke You need money to be a capitalist.