[latchkey]

I read the comments and I think that people are missing the crux of the issue:

mold is a product, not a business.

In the end, it doesn't matter if it is open source or not. As an engineer, you're stuck trying to sell the product, which isn't a service.

The service would be support and that's what he was rather successful with, given it was only one single niche product.

If he had taken mold and built it into some sort of larger service (maybe a CI/CD system? or something that did analytics on how mold improved developer happiness), I think he might have seen something closer to the 'big profits' because then it would be easier to justify paying for.