It's not degrading the access of other customers. Torrents can but for a completely different reason than bandwidth hogging, torrenting can cause problems because so many different people are connecting to a single user on their network and requesting data. That being said, it's a flat out lie that they can't handle that without throttling the speeds. In fact, throttling does absolutely nothing to help the issue, it's a lie they used to justify slowing down potential pirates because they're also a cable TV company. Bittorrent traffic can be easily managed by a large ISP.
As to your comparison, Netflix is NOT a data whore. Netflix isn't sending all of that data to Comcast customers, Comcast customers are requesting that data from netflix using the service they've already paid for. 20mb/s of netflix data has absolutely zero impact on other users from 20mb/s of http data or ftp data or any other kind of data. If I pay for 20mb/s then I have every right to use 20mb/s at all times. It doesn't degrade service unless the company is lying about their capacity.
