At the same time, I could be that OpenStack's API is superior to VMWare's. With a fleet of servers, you want to automate as much as possible - meaning that at the end of the day, API trumps GUI.
It reflects the bizarre decision VMware made when they wanted only sell to the top end of the market: the biggest customers are also the most likely to have the resources and incentive to build tools around that API. The small to mid scale shops depend on the GUI tools far more.
they would be talking about vmware ESX\vsphere not workstation.