“The cable industry is still the predominant distributor of many shows,” he writes, “and don’t think for a second that any cable exec is willing to give up the control they now enjoy to Apple. Not now, possibly not ever.”

There is no set-top cable box that doesn’t suck, says Agreda, a filmmaker and 3D animator. The cable companies like it that way, and the last thing they want is for Apple to swoop in and replace a broken user interface with one that works for users.

The cable executives saw what Apple did to the music industry in more innocent times — when the iPod was expensive and Apple was a flea on Microsoft’s (AAPL) back. That won’t happen to the cable monopolies, not on their watch.

Apple could make a business case to the content creators that an Apple TV set top box would make them — not just Apple — money, Agreda writes. But it has a steep wall to climb:

“If Apple continues to demand something on the order of a 30% cut, that may never happen,” Agreda concludes. “In that case, I would love for Apple to show us all what could have been… and see if the companies who said ‘no’ respond.”

It’s a smart piece. You can read it here.