* A mac is required for iOS development, so it can be used as a build server for teams working in Xamarin. Possibly used in other cross platform mobile development workflows. (Who: mobile developers, Why: to run builds)
* People that need more I/O than a macbook pro can support. In addition to the I/O a MBP has this has 10GB Ethernet, 2 USB A, HDMI, and a dedicated power slot. It's also significantly cheaper than the iMac Pro, while also having 10GB Ethernet. (Who: People working in video, photography, and anyone that heavily uses a 10GB network. Why: Better connectivity)
* Groups with existing macos server applications that want a headless server with cheaper/newer hardware than the Mac Pro or old Mac Mini. (Who: companies with macos server programs running. Why: It's newer better hardware)
* People that want a very small computer. (Who: Everyday consumers. Why: Small footprint. It's the cheapest Mac for people that like MacOS but don't the need portability of a macbook or the monitor of an iMac.)