"Instead, it is all you can eat, until Comcast says that is all you can eat."
No. A year or two ago, Comcast clarified their position on bandwidth usage as allowing you to use 250GB a month. This is now visible on their account, although I always have to poke around to get it: After logging in at comcast.com, go to the Users and Settings tab and look in the middle column. There's a link there to click that will let you look at your last three months history. I have 16GB in April, 80 in May, 57 in June, and 7 on my current billing cycle. They no longer advertise "all you can eat" and you are provided tools to see what is going on.
It is still bizarre to me that you can't pay for more usage, and you are free to disagree with the policy in philosophy or in detail, or to be annoyed at how much brow-beating it took to get Comcast to this point, but they are no longer just randomly cutting you off when you silently cross an arbitrary standard. It is now cutting you off when you cross a public threshold, and you can easily see where they think you are in the month.
Other comment - 250GB/month is less than 800Kb/sec. Cheap DSL is faster. Hulu uses 1Mb/sec. If you are one of those people who like a TV playing in the background, you can go over your cap just from running free television 24x7.
"I work as a entertainment industry consultant, and depend on cloud services such as Dropbox, Simplenote, Google Apps, and Google Docs for day to day work. I use streaming online services such as Netflix, Xbox Live, Playstation Network, and Pandora every day for both work and play."
Not sure where you get SDSL from cable modems, either.
Irrelevant. You imply, bordering on asserting, that using residential accounts for business purpose. That's precisely what telecommuters do.
So I ask again: should every telecommuter get a business line?
Furthermore he's using the same line for business and private use, should he get two different accounts? Should every telecommuter in the world get two different accounts to please you?
Finally, do you know for sure Comcast does not have the same kind of limitations on their business accounts than they do on their non-business accounts?
Both of these utilities have sliding scales (at where I've lived in California) which become punitive at higher levels. Comcast could do that same as long as they provided reasonable visibility.
Comcast does not charge by the megabyte.
Instead, it is all you can eat, until Comcast says that is all you can eat.
This guy was actually using his residential account for business purposes.