I still to this day chuckle when I remember a post on here, where someone was so adamant Hyper-V was better than vSphere
If you sign up to VMUG advanced account for $200, you can get full licenses for vCenter, vSphere and VSAN
To be fair, those were dark days and HyperV was new for MS. It's a much more mature product now and the delta is a lot smaller. Some people will choose HyperV because, well, it's technically manageable through a nice easy to use GUI. VMware can be a bit daunting the first time you use it, or install it for some.