Agreed. A cap and floor doesn't necessarily fix the problem. It limits the range of options, but a more balanced local revenue share would provide a more level playing field.
With a cap/floor, you're still going to have smaller markets sitting at the floor and the big markets at the cap. For NFL where basically everyone is operating right around the cap, is it just a function of it all being national broadcast arrangements so you can't have local TV deals, and thus every club has a similar amount of money?