His business model is very appealing to the customer: pay only once and receive all future versions.
The "downside" is that, once market saturates, you have to come up with a completely new product.
That's basically how almost all games work tho (with a handful of exceptions) - most people eventually get tired of playing the same game and move on to something else.
Out of curiosity, did you read the full article? It does a great job in making the point that disease/not disease may not be the right question to ask (which is a good thing because it isn't straightforward to answer).
