Since we are talking about the USA, I am sure the big corporations will get their way, and that someone will go on Fox News and declare that this is capitalism and that anyone who disagrees is a commie.
I think it is more likely that the carriers are trying to create an artificial shortage of bandwidth so that they can manipulate price - rather like a telecom incarnation of Enron.
Buying more of the spectrum is a true way to monopolize the cellphone industry, but by having more of the bandwidth they aren't forced to pay costs of upgrading their systems and cell towers, which is even more expensive and tedious effort to do than to purchase more airspace.