I know a lot of people attempting this and they mostly seem to be flying under the radar, or at least have nowhere near the cachet of a startup. They are often bootstrapped, frequently for lack of other options.
For those of us who don't want to be in the pressure cooker or are turned off by the hype machine, these businesses are a viable alternative route toward independence and possibly achieving a significant impact. The fact that they have become as attainable as they are is I think also something quite remarkable.