Cost. We're a small company, five person team and we need a development environment. All our stuff is built around VM and Docker. So scores of little test nodes that get run, or beta environment in the cloud was costly (>$300/mo base, sometimes 3x). For $1000 we put a box in the office we all VPN to that runs all the necessary VM and Docker. The variable, sometimes expensive cost for Test/Beta in cloud was replaced with low fixed cost.