I mean, to a certain extent, running a startup often means convincing people of a problem they didn't know they had. I think a more accurate simplification of their post mortem is something like:
"I had a problem and solved it for myself. I thought it was a problem others had, but it turned out most people didn't think it was a problem, and I couldn't convince them otherwise."
This is actually a very effective approach if you have something to offer they both want & need.
It feels like a mature version of this product would be ideal for publishers and other customers of authors.
However I suspect we are not there yet technological wise and therefore he was unable/didn't attempt to sell the product to these companies.
To do what? Auto-generate new books about a particular series when the writer doesn’t want to write any more?
Possibly with some prompting help from a ghostwriter?
Lesson learned I hope: It seems to me that the author wanted to be an entrepreneur foremost instead of solving an acutal problem. What the author wanted was their own startup with the accompanied startup experience, and so the "problem" was rather secondary and maybe even thought of after that desire?
I mean:
> It turned out that writers actually like to write themselves, and the current level of technology was just not good enough to make them really satisfied with whatever output they got from my product.
Really? It continues:
> Even though nearly everybody on this planet has heard the “machine learning” buzzword by now, the less technologically experienced hobby writers that I talked to didn’t have a real understanding of what they could expect from my product. This fundamental knowledge divide really made me think about how to reach this group of people.
Again, this really gives me the impression that you're not trying to solve a problem. You're "thinking about how to reach this group of people" to sell them your dream of having a company, not something they want or need.