I’m not the OP but I see the connection as Google seeking growth and revenue by applying their general search know-how to areas outside of the Internet.

I followed search appliance closely when they announced it. It was interesting technically and looked cool, but seemed like a dead end similar to desktop as applications were largely moving off of racks/desktops. I was right about that, but I expected Google to offer a web-based search appliance and they never did beyond custom searches. Algolia fills that opportunity nicely now.