TGIF: Of Bumblebees and Competitive Courts

Considering that what liberty we continue to enjoy in the West is a product in large part of competing legal institutions operating within overlapping jurisdictions hundreds of years ago, it's curious that so many libertarians still believe such an order -- an essential feature of free-market, or natural-law, anarchism -- would be inimical to liberty. Why wouldn't that which produced liberty be up to preserving it?