This surprises me. When I had Comcast Business Cable installed at my home, the telephone rep got the install address, paused a moment, asked, "Is that a residential house?". I said yes, and all was fine. No raised eyebrows from the installer either.
In fact, my boss/company owner, who lives outside Scottsdale, who can't get more than 144kbps IDSL got so sick of things that he ordered a first, then a second bonded T1 to his house, without any hiccups.
If I had to guess what the actual issue is; I think my neighbourhood is connected to some rather old copper lines and they can't make the kind of reliability guarantees that they make to business clients on it, and they don't want to upgrade or replace the copper. The neighbourhood is fairly new but the area it's connected to is fairly old (road paved and utilities put in way back in the 80s/early-90s for other places near by). This is all speculation from knowing the area and the fact that their residential services has had a number of unexplained outages/issues with bandwidth fairly often (6-7 times a year it'll be out for a few hours or very very slow, and they say they are working on it).
In fact, my boss/company owner, who lives outside Scottsdale, who can't get more than 144kbps IDSL got so sick of things that he ordered a first, then a second bonded T1 to his house, without any hiccups.