I wouldn't self-identify with either of the two characters here, but then again they're characters. That said: yes, there are lots of small software businesses out there. Many of them do leave the owners pretty well off. Not all of them require huge amounts of work. BCC is very much not the most successful one out there.
The reality is that it's a little more than "20 minutes a week" if you tally up all of the labor over the lifetime of the product, but then again, most people don't include how much they've worked in the past when they're asked: "How much time do you spend working each week?"