Hi, I'm the author and I'm delighted that people are still interested in this topic.
There are a lot of great comments, but I'd like to collect and respond in bulk to the ones about keiretsu, since there are a lot of misunderstanding about them.
1) It's not the keiretsu, it's X.
It's not just the existence of keiretsu in isolation. They keiretsu produced incredible innovations in the 60s and 70s. It was the combination of the keiretsu control and the shift to domestic markets (which the keiretsu also controlled) that killed the PC software industry in its infancy.
2) Amazon, Apple, Facebook, Google are like keirestsu.
They really are not. In fact, they operate on a radically different philosophy. Keiretsu would be willing to lose money (and a lot of it) in order to keep business in-house. Their supply chains were owned, integrated, and exclusive. Employees did not leave their keirestu group It fostered innovation as long as they were export facing, but it fell apart once they started to focus on the domestic market.
Thank you again for reading. I'm happy to discuss.