I think a more nuanced explanation is that the problem isn't the amount of regulation but the nature of the regulation. If we simply add up all the rules, healthcare is probably more regulated in the US than anywhere else in the world. The difference is that in other countries the rules are designed with the intention of making healthcare accessible to everyone. In the US, the rules are designed to maximize profits.

A less nuanced explanation is to agree that in an unregulated market, this type of excessive rent seeking would not exist. The old and sick would simply die in the streets. (Actually that's not quite fair since in an unregulated market we wouldn't have streets.)