I think it is because, for a lot of people, Lisp is fun.
If Lisp flourishes, more people would get to use it at work.
Lisp not flourishing means less fun.
Also, when I've worked in Lisp it just seemed like the right way to do things. Everyone likes to do the right thing, so anguish results when you seem denied the opportunity to follow the path you feel is right.
That said, I think the author was right and the community issues and ease of building your own solutions will limit Lisp as a language family.
I can definitely subscribe to the idea that Lisp is fun. The application I have been writing (featureful chat application like Slack) has a server side completely written in Common Lisp by myself. Why do I work on it even though it's unlikely that it will ever draw anyone away from Slack?
Because it's fun.
Is it possible to do the same in another language? Sure, Slack is proof that it's possible. But would I have persisted in actually doing it without any hope of profit? No, because programming in other languages is a chore, and the only light at the end of that tunnel is the finished product.
With Lisp, the journey is a reward of its own.
Yes, I know the same thing has been said by Haskellers and others, but I doubt it was ever said by a C++ programmer.
If Lisp flourishes, more people would get to use it at work.
Lisp not flourishing means less fun.
Also, when I've worked in Lisp it just seemed like the right way to do things. Everyone likes to do the right thing, so anguish results when you seem denied the opportunity to follow the path you feel is right.
That said, I think the author was right and the community issues and ease of building your own solutions will limit Lisp as a language family.