The thing people forget about Kinect is that microsoft invested enormous amounts of money buying up licences and IP to make their system work. Much the same as apple did when they completely took OpenNI off the market along with the NiTE middleware.
And even then Kinect 1.0 was still a pretty average system - it was low resolution (320x240) and very jittery and unreliable.
Kinect 2.0 was the serious game changer and it had even more huge amounts of money throw at it ... and a set of hardware that included a TimeOfFlight sensor that even to this day no one has been able to replicate at the price point the Kinect 2.0 hardware was sold for. ( basically the same price you buy an Orbbec for today ) except that Orbbec ISNT a TimeOfFlight based system.
As such Kinect 2.0 was a heavily subsidized product - with an SDK that was released grudgingly by Microsoft almost at the end of the product life - and then effectively abandoned by MS and the costs most likely written off as a loss.
No commercial player coming into the market place now is going to give that technology away for free.
Apple took what was effectively an open source platform and destroyed it to get at its technology
MS took most of gestureteks IP and then pretty much wrote it off as a loss at the end of Kinect's life.
Carnegie Mellon took the openPose system - make it free for no commercial work - then placed a 25,000 per year fee on it for commercial work.
YES - Nuitrack is a per seat / per end user system
AND - we dont yet have a fully published pricing structure for the Orbbec Skeleton system
Yes TVico is the same hardware basically as the Persee - but with Nuitracks code running the engine.