That's not even the problem. There's a reason that the free market can't work here: communication cables are a natural monopoly - it doesn't make sense for each provider to run their own.
As a result, Internet access is effectively a Utility and needs to be regulated by one. Well, either that or turn over all of the physical cable networks to the (state) government, but that has clear downsides.
This fight makes no sense to me. If the cable companies are concerned about revenue, they can just cancel the line item for "equipment rental" and just raise the base fee an identical amount. Boom, done.
If they are worried about losing control... I don't understand why. They own the pipes, so changing which box makes the connection ultimately doesn't alter anything.