To be clear, Hyper-V is not "free" as in "no cost". It's "free" as in "no additional cost": Most who have Windows VMs in a virtual datacenter have Windows Serve

To be clear, Hyper-V is not "free" as in "no cost". It's "free" as in "no additional cost": Most who have Windows VMs in a virtual datacenter have Windows Server Datacenter licensing which allows infinite VMs per processor core. So if you have Windows Server VMs, you can already use Hyper-V as your hypervisor, but many still prefer VMware because it's seen as more stable and secure than using Windows hypervisors underneath your Windows VMs. VMware certainly adds value, but not infinite value, when most of its customers already are licensed for Hyper-V anyways.