Wikipedia even tells me that some libertarians "seek to abolish capitalism and private ownership of the means of production."

It says that because prior to being used by right wing intellectuals in the 50s libertarian was a synonym for anarchist, and anarchism is a kind of communism. No one talking about libertarianism without qualifying it as "left libertarianism" means anarchists anymore, because anarchists don't want to be associated with a capitalist political philosophy, and you only see "left libertarian" in contexts where "anarchist" will scare people. The two aren't really related; Murray Rothbard liked Proudhon and Spooner because they were still living in the world of cottage industry and didn't place as much emphasis on anticapitalism as those who actually experienced modern capitalism did, and tried to form an alliance with anarchists in the 60s because 60s anarchists were hippies and hippies were gullible, much like the Republicans did with southern racists, but it didn't last because even the hippies weren't that gullible.