I would argue for the existence of a treadmill effect on these things.

Although this may not have been true at the beginning, it arguably did grow to meet that standard. Cable TV is still fairly young in the grand scheme of things, though, so I would say there isn't enough information yet to conclude whether a TV paywall improved content overall.

Also, it's important to remember that TV relies on the data-weak and fairly inaccurate Nielsen ratings in order to understand its demographics and what they like (and it's even weaker and more inaccurate for pay cable). This leads to generally conservative decisions regarding programing. The internet, on the other hand, is filled with as much data as you wish to pull out regarding the people who use your site, on both a broad and granular level. This allows freedom to take more extreme changes of direction, because there's a feeling that the risk is lower. So the two groups really aren't on the same playing field, and their motivations for improving/shifting content potentially come from different directions.