So what he said is that if its a viable, sustainable business that the founder wants to do, that adds value to society, but there is no exponential growth on the horizon, then it should be shut down.
Because (and he said it explicitly), the only thing that makes a startup truly a startup is the exponential growth and nothing more.
This is just crazy, exponential growth is extremely rare in business and only happens in situations like the way Facebook grew, by upon sign up getting the whole list of email contacts of the new user, and sending invitations to join Facebook to all of them.
Most of the times in business, linear growth is what happens. what's wrong with a 20 employee company that adds a ton of value to society, operates for 30 years and gives the founder and family a comfortable life, isn't that more than enough and worthwhile pursuing?
Exponential growth is impossible to predict and only comes by accident, it's like chasing the rainbow.
Just focus on building a real business that you really want to dedicate your life to, preferably borrowing as little money as possible if it all, how about that?