The X39 was originally intended for home/consumer use if you think back to the pre-release testing we did at the time, & MINIX had made soft announcements that the X39 would essentially be the successor to the U9-H as well. (One can't help but recall the disappointment on the forum when the X39 was essentially repurposed.)
Sadly, that plan just didn't work out. MINIX couldn't iron out the firmware issues surrounding HDR functionality or overall compatibility with home theatre hardware & the device was essentially repurposed on the fly for industrial/commercial use soon thereafter.
If one isn't using an HDR TV or any kind of home theatre hardware, the X39 is actually quite capable & adequate as a consumer level device but the problems begin when consumers purchase it without first reading up on any potential constraints that may directly affect them which is ultimately why MINIX had to make the decision they did.
Having said that, was there really anything stopping MINIX from recruiting some additional skilled software engineers & developers to continue working on the X39 post release to address the known issues & open an entire avenue of additional sales back up again? Probably not!!
The main question remains why didn't they? I guess we'll now never know as that opportunity has now long since passed.