I don’t know if libertarianism courts a different audience in Brazil, but in the U.S. it has a very rabidly right-wing audience who effectively want to tear down as much government as possible, and who view “your freedom ends at my face” as an insult. It’s the ideology of an extraordinarily unregulated market – a true “free market” – which is a monopolistic and wildly unethical disaster waiting to happen.
Anarcho-capitalism, which your username references, is all of that, only more. So you might understand why effectively everyone here is going to treat that with extreme suspicion.