The data seems a bit suspect. What exactly are they measuring? They have comcast rated very low, yet i've never heard of anyone with comcast who ever had problems with a relatively trivial internet task such as streaming netflix.
I'm on Comcast and I can max my 100Mbps connection 24 hours a day for weeks on end if I wanted to. In fact, I can't recall any time in the last 10 years when I couldn't max out my cable connection any time I wanted.
Comcast has its own netflix CDN. I can stream 3d from netflix as long as I use comcast DNS.