While I still have very mixed feelings about the world of Docker, if you are going down that road, having smaller base distributions can be very helpful. I was pleased to see the minimal Ubuntu announcement a few months ago.
I like that they took it step further and made the minimal version the standard official release version for Docker. Running docker run ubuntu:18.04 will give you the minimal server version of 18.04 LTS.
Defaults matter, and I think this was a smart move by the Ubuntu folks.