I think the upload limit has something to do with the Docsis protocol that most of their equipment operates (cable TV) under. I believe that the newer version protocol (Docsics 4) should allow for much greater speeds, up and down. I have no idea how long it will take these companies to update to this version.
The current widely deployed version, DOCSIS 3 supports up to 1Gbps down, 200Mbps up. 3.1 which isn't fully deployed but is available in most major markets is up to 10/1.
I think the main issue is in how Comcast allocates the different channels. They prioritize download because it also serves TV customers, while upload is only used for Internet.
>I think the main issue is in how Comcast allocates the different channels. They prioritize download because it also serves TV customers, while upload is only used for Internet.
Comcast has an inherent conflict of interest, in that they are a middleman for high margin TV subscriptions. Better internet obviates the need to purchase TV subscriptions from Comcast, so I would conclude they're dragging their heels on purpose.