Absolutely not. Harmful monopolies from the old AT&T monopoly (created by government regulations), to the U.S. Post Office monopoly were created by the state. The U.S. Post Office, for example, maintains its monopoly on the lucrative first class mail market by having the state outlaw its competition.
Take for example Judge Learned Hand’s indictment of ALCOA. What ‘crimes’ was ALCOA punished for? To quote Hand:
“It was not inevitable that it should always anticipate increases in the demand for ingot and be prepared to supply them. Nothing compelled it to keep doubling and redoubling its capacity before others entered the field. It insists that it never excluded competitors; but we can think of no more effective exclusion than progressively to embrace each new opportunity as it opened, and to face every new- comer with new capacity already geared into a great organization, having the advantage of experience, trade connections and the elite of personnel.” [Alan Greenspan, "Antitrust" published in Ayn Rand's Capitalism: The Unknown Ideal]
In other words ALCOA was being punished for being too good a company, too competent in its management, in other words Alcoa’s crime is that it is too competitive.