Part of it is terminological confusion, which is, to some extent, deliberate.
The original definition of "free market", as defined by Smith, was all about free competition. In other words, a market with monopolies, cartels, and other forms of collusion or regulation that inhibit competition are not free, and this applies to monopolies and barriers to entry that arise naturally. Other classical economists generally used that definition.
Smith also explicitly stated that an unregulated market will usually result in a monopoly, and that government intervening to prevent that is not a bad thing (while also calling against tariffs, government-protected monopolies etc).
At some later point, the laissez-faire crowd basically asserted that 1) Smith was wrong (in that unregulated markets can be monopolized), and on the contrary 2) any government regulation makes market less competitive, and therefore 3) the only free market is unregulated market, effectively conflating the two terms.
For those who don't subscribe to laissez-faire economic theories, it makes sense to continue using the traditional definition, and carefully distinguish the two.
The original definition of "free market", as defined by Smith, was all about free competition. In other words, a market with monopolies, cartels, and other forms of collusion or regulation that inhibit competition are not free, and this applies to monopolies and barriers to entry that arise naturally. Other classical economists generally used that definition.
Smith also explicitly stated that an unregulated market will usually result in a monopoly, and that government intervening to prevent that is not a bad thing (while also calling against tariffs, government-protected monopolies etc).
At some later point, the laissez-faire crowd basically asserted that 1) Smith was wrong (in that unregulated markets can be monopolized), and on the contrary 2) any government regulation makes market less competitive, and therefore 3) the only free market is unregulated market, effectively conflating the two terms.
For those who don't subscribe to laissez-faire economic theories, it makes sense to continue using the traditional definition, and carefully distinguish the two.