Markets naturally tend towards monopoly. The idea that monopolistic incumbents are always disrupted in laissez-faire markets is incorrect; incumbents have plenty of non-regulatory levers to keep themselves on top once they stay on top: kickbacks to suppliers and distributors, industrial espionage/sabotage, slanderous ad campaigns, cornering the markets for inputs, forming cartels with monopolistic producers of complementary products, poaching key employees, etc. If you think the government is the only barrier to competition, you haven't given this enough thought.
