I have cable access, but I rarely use it to watch local broadcasts, which are useful when severe weather moves through the area.
I know two families who do not have cable because they want to exercise control over what their children can access.
I can appreciate the local weather angle, but increasingly, local cable networks are carrying these stations as the cost declines (along with aerial broadcast viewership). Additionally, you have many other options for local information, including the internet (weather.com, www.erh.noaa.gov, etc.) As for parental control, that's a real concern, but all TV's made in the past decade have V-Chips, and cable network boxes frequently have additional content controls. I use the latter in my house to limit program and movie ratings for the kids' benefit.