The whole period of NoSQL was particularly sad one. A couple great things emerged from it (Redis etc al) but for the most part it as all smoke and mirrors.

The worst was the amount of people wanting to be the next Ed Codd and being nowhere close to his mathematical background.

I'd call it a necessary phase rather than sad. People needed scalability fast, key-value stores are natural to shard, so they did that first and then we got better distributed DBs later. Even Prime Google was on bigtable for over a decade before spanner.