Because when they’ve moved everybody off the current analog broadcast frequencies, they can then auction those frequencies off to the highest bidder, and use the money to buy more votes.
There is a big discussion in the amateur radio circles about that very thing - I think you are right on target.
DING, DING, DING, DING! We have a winner!
The FCC controls the "public airwaves". They are controlling, or attempting to control, the entire electromagnetic spectrum, they see dollar signs and there's nothing "free market" about it. Just a bunch of goobermint bureaucrats messin' things up (again). I spent the better part of 18 years dealing with those nitwits at the FCC in the wireless industry. I could tell you stories that would make your hair curl......
BINGO!