If you really think there are serious developers out there waiting to write a one off driver for a product with a market penetration running to the thousands, then good I will agree with you on all your points.
However the reality as it stands, and as it is likely to remain, is that someone has already reverse engineered the driver for the Khadas dTV card and plugged it into the Linux ecosystem.
Since there is already a working apk (all be it a rather limiting and limited one) available for Android developed by the manufacturer I can see NO prospect of another developer taking the time and trouble to reinvent that wheel with zero help from the manufacturer and zero chance of them getting any return on their invested time. It seems however that Khadas themselves have no ability to influence the dTV board manufacture with regard to release of their propitiatory software once they supplied the original DTV APK, and that manufacturer has stated that a separate driver will not be developed (in fact it seems unlikely they will bother to do any further software development for the board). The DTV software bundled with the Android released by Khadas is likely to be the only software ever produced for the card in Android.
Android has its place (on phones) and even makes a descent media player when fully licensed in the form of full Android TV, but in just about all other implementations it cripples the available hardware functionality (AC3 -the most popular audio format for TV broadcasts doesn’t even work in Khadas Android because they didn’t bundle the license) and offers a truly terrible user experience. This is why most people who want to use their boxes as media players quickly migrate to more specialist and optimized OS’s such as CoreElec. Kodi just about runs on well implemented Android boxes, but it will never have a stable and fully functional PVR to run the dTV board because it is missing the essential backend infrastructure, and the people who write the popular apps such as TVheadend have stated that they will never bother porting to Android. The one person who did manage to port TVheadend to the Nvidia shield doesn’t seem interested in other boxes and has seemingly abandoned the project at this stage.
If you disagree then I invite you to wait for that Android driver you want whilst I get on with using my hardware before it becomes redundant in a few years time.