It's for business. I currently run about 10 OS X server instances on Mac Mini and needed to test the larger horsepower / put that machine in temporarily to do things like directory migration. Also, I've got several thunderbolt 2 drives and Pegasus towers and the Pro can rip through imaging and data migrations in hours instead of days.
I really, really love it. But you're right that it's real power is unused (the GPU/CPU rarely get over 25% usage no matter what I'm throwing at it).
However, I'm messing with docker and virtual machines and having the RAM and CPU really will shine then.
@Jin Yup - funded projects can work well for hardware purchase dreams :-)