Libertarians are often anarchists because they believe the state cannot exist without violating the NAP. The state (By definition as an entity with a monopoly on the use of force in a geography) thus uses violence to conquer a land and takes for itself rights that naturally belong to the people.
>You mean to say that a workers' occupation is an act of aggression or force,
I don't see how this follows from anything I said. I can't connect it so, I can't respond.
>You're also insisting that "libertarianism"—a political philosophy—tells us anything about morality or ethics. That's a much stronger position than what, in my experience, even U.S.-style libertarians tend to espouse.
I'm not insisting anything. I'm giving you the definition. I'm a Libertarian, and that is what we believe. This is consistent across the US, and in my experience, among libertarians across the world. This is consistent with the founders of the Libertarian party in the 1970s, Rothbard and Nolan, and with the philosophical groundwork and economics that they took inspiration from.
FWIW, wikipedia is a crowd sourced entity. It is not authoritative, and it is often quite biased when it comes to political topics that leftists have a strong opinion about.