Even if you were to scope it just to software/SaaS product companies, there's minimally hundreds of these in the world and dozens of them have HN accounts. Most don't post on threads like this, so I feel the need to pipe up and say "This is quite doable, and done, much more than you might expect."
I run a small software company (two, technically). Products include Bingo Card Creator (http://www.bingocardcreator.com), Appointment Reminder (https://www.appointmentreminder.org), and occasional offerings for training for other software companies. I used to do consulting, too, but quit to focus on products.
I'd describe it as "modestly successful." It's the sole financial support for my wife and I. I'm the only full-time employee of the business (for a very quirky understanding of the words "full-time").