A few other protocols have been used "over power" such as phone oover power (for satellite) and networking over power (computer networking) and have had some success but not as reliable as the current HFC network or where Fiber is now coming into play. I have always been hesitent with playing with power, and I think the executives were just looking for a "unique" item that people would be interested in. I agree that this is not the future for our industry.
This is CABL.com posting #145330. Tiny Link: cabl.co/mLYc