Why is #2 a violation of NN, but #4 is not? Does it really matter if the video is transferred using IP on top of "internet" frequencies, or IP on top of "video" frequencies, or QAM on "video" frequencies?
In #2 the service is delivered over IP and the same last mile wires as other internet traffic. It's not "the internet", but it competes directly with the internet for last mile bandwidth, just like a Netflix or YouTube cache installed on the ISP's network.
It directly competes for last mile bandwidth regardless--the frequencies on the coax can either be used for internet or a dedicated video service but not both.
Would you really require cable ISPs provide you an internet bandwidth of X and video bandwidth of Y instead of internet bandwidth of X+Y?
There's shades of grey here - anything you lay in a fixed diameter conduit is competing for bandwidth in the sense that you could pull another wire.
Consider an alternate history, where TV was invented after the internet. ISPs propose to offer TV service (exempt from data caps of course) at the expense of last mile bandwidth, which is otherwise subject to caps. I think that would be recognized as a net neutrality violation.
It feels unreasonable because we know the cost of providing television service scales with the number of subscribers, not the usage per subscriber. Of course, that's also true for internet service outside peak hours - a fixed monthly cap does not match the unit costs of providing internet at all.
I think pragmatic regulation would exempt existing cases like this. We wouldn't permit a new case like it in the future, though.
It's because we see TV and Internet as different media entirely, even if they deliver the "same" content. That is outside of the scope of NN discussion currently. In the same manner, newspapers and TV are subject to different regulation even if both deliver the "same" news. It's hard to come up with rules which would apply for all media - even maxims like the 1st amendment aren't simple to implement.
In theory, the problem you refer to should be addressed by anti-monopoly laws (NN is a tool to address a different problem).
