I understand your point and agree with corporate responsibility and have a dislike for profit at any cost, etc. Nevertheless, to date, despite AM's obsolescence, Radio One has kept the WBT/1110 facility on the air and presumably in compliance with FCC regulations. If AM is such critical infrastructure, let the government pay for its upkeep. Most of the rest of the world has already moved on.
An FCC license does not (and should not) come with a perpetually unbreakable obligation, however. The owner is free to sell its right to operate the license, or facility itself, or some combination of those. If there are no interested parties, the license can be returned it to the FCC at any time. The only thing "public" is the license itself. Not the transmitter and towers, or the land beneath it.