I think the author thinks the primary motivation for open source is companies making a donation out of the goodness of their heart.
While that does happen, i dont think that is the main cause. Most companies participate in open source for their own selfish reasons. Sometimes that is to attract talent, sometimes it is to attract people to their propreitary platform, sometimes it is to commodify the parts they dont want to compete on, sometimes its something else. The companies do get benefits here. They are probably going to continue so long as the benefit > costs.
As for non corporate open source. It may not be a healthy hobby, but i dont see anything changing here. If people have been doing it as a hobby for the last 20 years, why would they stop now?