The issue typically is not that Comcast is oversubscribing their network, its that there is more traffic trying to enter their network from a specific peer than is provisioned. This is what was at the core of Cogent/Comcast dispute. If your position is that an ISP should be required to provide as much capacity to any peer who wants it than that is at least an intellectually honest argument to make. You could further extend that argument that it should be required to peer with anyone who demands it. If you and I started a transit provider tomorrow should, won a deal with a video provider should Comcast be required to peer with us?
This is really what should be at the heart of these discussions, not abstract claims about who is throttling who.
Its not like the traffic is coming from no where. The traffic is being requested by Comcast's customers. So yes, they should be able to support the traffic their customers are requesting. If its not legitimate traffic, feel free to drop the peer.
My arguement is that ISPs should deliver the product they sell to consumers. If the consumers demand for Netflix goes up, the ISP should adapt to ensure proper bandwidth at peak. The internet on the whole and interconnection between companies is hardly static. Its constantly growing bandwidth wise and its really very simple to increase bandwidth to other providers. Technically its fairly easy without all the legal bits that get added in to peering agreements.
Comcast wasn't negotiating the Netflix, it was negotiating with Cogent for how much bandwidth Cogent wanted. Netflix just happens to be a large driver of Cogent's interconnect needs but not the only one. Looking from the other direction Netflix could have used additional transit providers but elected not to for whatever reasons. I would humbly suggest that very few people understand the complexity of the product that an ISP delivers.
This is really what should be at the heart of these discussions, not abstract claims about who is throttling who.