Don’t consider porn a free speech issue. The courts are just wrong about that. I consider “speech” to be a free speech issue.
A possible alternative to the requirement to host anything is the public interest standard used by the FCC. That disallows particular profanity and porn for public broadcast: https://www.fcc.gov/consumers/guides/obscene-indecent-and-profane-broadcasts presumably since any kid could pick up a broadcast (never mind that they get it all from the internet nowadays)