You are technically correct, but but missing the real issue.
I have 0 interest in buying a fast line to comcasts internal services, they are selling me a way to connect to the rest of the internet.
I have 0 interest in buying a fast line to comcasts internal services, they are selling me a way to connect to the rest of the internet.
Whether it's what they intended to sell or not, ISPs, through their own marketing material, sell a connection to "the Internet", and unfortunately for them that term cannot fairly be applied to just Comcast's network anymore (though it would make for a comical court case).
If they can't provide what is advertised, specifically "Internet access", then it's false advertising and I expect, and will fight for, my money back.
A workaround would be to rely on an IPv6 tunnel broker or a VPN tunnel to a VM in some datacenter. As long as the tunnel is unaffected by peering disputes, your traffic over it will live at the other side of the divide between content producers and consumers. That gives a far better experience than relying on a last mile operator to give you access to the broader Internet.
Speaking of which, does anyone know when hacker news will support IPv6?