Patrick wrote "year in review" posts going back to 2006, and they include full numbers, so you can see for yourself. Profit margins in 2014 (the most recent review) were at a whopping 60% across all his businesses. (See here: http://www.kalzumeus.com/2014/12/22/kalzumeus-software-year-...)

> closing down

He sold his SaaS businesses, and they are operated by other people. Here's a podcast episode about it: http://www.kalzumeus.com/2016/08/26/kalzumeus-podcast-episod...

They are still in operation, and presumably still profitable:

https://www.appointmentreminder.org/

https://www.bingocardcreator.com/

> Growth or death

Not really. Moving past patio11 as an example, just look at local businesses in your community. The ones that have been there the longest (> 50 years) have undoubtedly gone through periods of both growth and decline (I don't mean decline toward death, I mean decline for a bit and then start growing again). Many of the ones that have been there for about 20 years will have reached a sort of "asymptote" of growth--they would have grown for the first 10 or 15 years and then stabilized around a size that feels "comfortable". There are many more businesses in the world than just start-ups and public companies.

Software built by 1 person will always have good margins. According to his numbers, BCC was making $60k in good years. 60% of that is $36k, which is a fraction of what a solid Dev can make (and an even smaller fraction of what he patio11 was making consulting). Clever side project income for sure, but not a staggering work of business genius.