The free-enterprise system, or capitalism, is the freedom of an entity to make profit, without being coercively taxed or manipulated by the state. Beyond this, "Capitalism" may or may not entail other attributes and features.
While attempting to justify failing to pay royalties to patent-holders of technology he was selling, Harry Mudd claimed that as a defender of the free-enterprise system he found himself in an ambigous conflict as a matter of principle. (TOS: "I, Mudd")
Prior to first contact with the Ferengi in 2364, the Federation had information that suggested the Ferengi reflected the worst aspects of capitalism, conducting their affairs on the principle of caveat emptor. This turned out to be correct. (TNG: "The Last Outpost")
Quark felt that Grand Nagus Zek's reforms of the Ferengi Alliance in the 2370s (specifically the introduction of tax) went against the "very spirit" of free enterprise, as it was free in his opinion. (DS9: "The Dogs of War")