I agree that Libertarianism (with a capital L ..."political Liberatarians") is a little contradictory. It claims to be about liberty, but is contradictory, since it embraces political means, which are factually speaking "anti-liberty". Are they better than other political types regarding liberty? Sure, but they still think a little bit of coercion is okay.
Small l, libertarians or "voluntarists / voluntaryists" are not political, and distinctly separate from political types. They are the ones that most people won't (can't) argue with, because they use logic and are usually good at pointing out the inconsistencies of the political types. That's often why political types run and cry, can't answer questions or insult. Their arguments often default to some kind of pseudo religious worship of authority and are often nonsensical.
I don't agree that Libertarianism makes people stupid though, it's far less egregious than say a liberal with a co-exist bumper sticker that supports forcible redistribution of other peoples property. Ummm....okaaaay.
I think it's impossible to use the political means to bring peace. It's not only my opinion, it's a fact. The best an imposed political system of any kind can do is create imposed order, which isn't really peace.