If you read more carefully, you'd have noticed that I stated that. I'm discussing morality, not US law. I also pointed out that prior to government regulation of RF spectra, there were indeed court cases between broadcasters, and they were settled quite nicely using the principles of homesteading. The point of the historical anecdote was to illustrate that the US actually handled the radio waves in a moral fashion at first, before the government decided to take over.
"If you read more carefully, you'd have noticed that I stated that. I'm discussing morality, not US law"
You seem to misundertand both US law and morality. It is not immoral to regulate radio spectrum so that it can be used to the greatest benefit of society.