It's not like there haven't been regulations that cause more harm than good, though--for instance, regulations on pollution that only apply to new powerplants, leaving old ones untouched.
Libertarianism treats regulation like engineering: Simpler is better, and the ideal solution is the simplest; complicated solutions add more points of failure, which leads to a more broken result.
A reasonable belief, given what happened before regulatory controls were imposed to prevent massive monopolies.