Capitalism has nothing to do with the free market. By which I mean that it has nothing to do either for or against the free market.
The term ‘capitalism’ was invented by nineteenth-century Socialists as a term of abuse, and they applied it as a contrapositive label to Socialism. (Proposition: ‘All Socialism is state control of the means of production.’ Contrapositive: ‘All conditions in which the state does not control the means of production is capitalism.’) In this original sense of the term, it most definitely does have to do with the free market, in the sense that it is a necessary but not sufficient condition. You cannot have a free market in a Socialist economy; and since the terms are defined as mutually exclusive and exhaustive opposites, by those definitions you cannot have a free market in anything but a capitalist economy.
Re: About a red herring
The term ‘capitalism’ was invented by nineteenth-century Socialists as a term of abuse, and they applied it as a contrapositive label to Socialism. (Proposition: ‘All Socialism is state control of the means of production.’ Contrapositive: ‘All conditions in which the state does not control the means of production is capitalism.’) In this original sense of the term, it most definitely does have to do with the free market, in the sense that it is a necessary but not sufficient condition. You cannot have a free market in a Socialist economy; and since the terms are defined as mutually exclusive and exhaustive opposites, by those definitions you cannot have a free market in anything but a capitalist economy.