Cable modems burst onto the Internet scene promising lightning-quick access far exceeding the dial-up connections of the day and beating the competing technology, DSL, by a long shot in the early going. DSL has chipped away at some of those early advantages, and some of the drawbacks of cable-accessed Internet remain.
Cable Internet technology excels at maintaining signal strength over distance. Once it is delivered to a region, however, such as a neighbourhood, it is split among that regions subscribers. While increased capacity has diminished the effect somewhat, it is still possible that users will see significantly lower speeds at peak times when more people are using the shared connection.
Bandwidth equals money, so cable's advantage in throughput comes with a price. Even in plans of similar speeds compared with DSL, customers spend more per Mb with cable than they do with DSL.
It's hard to imagine, but there are still pockets of the United States without adequate cable television service. There are far fewer such pockets without residential landline service meaning cable Internet is on balance less accessible in remote areas.