Connection speed is a solvable problem. Good internet is cheap relative to a salary. So while there'll be a transition period where people discover their Comcast cable connection isn't enough, when people take it seriously those'll get fixed.
Solvable, but not quickly. Even in the Houston area, you can live 30 minutes away and be in a pretty rural setting. Someone may have made that choice intentionally, not thinking they'd be required to work from home one day. Imagine owning a Prius as a UPS driver, and then being told you need to start using your personal vehicle for deliveries.
I agree, but also Comcast cable IS enough 99% of the time. He said she was having trouble with VOIP. You can run VOIP on almost any kind of connection. Definitely every modern cable connection is designed for that. And if it was "her computer" i.e. slow webpages, that is probably just a broken web application if it doesn't work remotely, or one that was designed (poorly) for an intranet.
Fixed how... Comcast is basically a monopoly in many areas
They have a monopoly on the existing cable infrastructure, but other ISPs install fiber or WiMax antennas.