I think I may have an idea why this concept hasn't gone over well on this forum. We ride small bikes. They weigh about 400lbs. For ease of calculations, lets say the rider is another 200lbs, as is the passenger. So the total weight is about 800lbs, roughly. Probably on the high side, but this is just an example, okay?
There isn't much room on our bikes. At 6'2" and 190lbs I'm cramped on my Maxim. And I'm sure I look like a circus clown on a tiny bicycle.
Like on a sport bike, the passenger is very close to the rider. Possibly even hugging the rider. When the passenger moves, 1/4 of the total weight is moving. That, in itself, is significant. And due to the proximity of the rider and passenger, the tablet would be very close to the passengers face. Probably too close to comfortably view or use. This would have the passenger moving even more to view and operate the tablet. The passenger would have to release their grip with one hand to operate the device, while leaning back to get to a workable distance. Wind drag, the change in balance, etc would be quite noticeable.
Now, lets take my neighbour's GoldWing as another example. It is over 800lbs empty. Add another 400lbs for rider and passenger. And another 200lbs for the contents of the side bags and trunk. That puts him at 1400lbs total weight, again just an approximate number. The passenger is 1/7th the total weight, which is not very significant. The rider and passenger sit with about 2' space between them, the driver also has a short backrest. The passenger has a backrest and armrests. Heck, they have a cup holder! In this case, the passenger can shift about without much if any noticeable effect on the bike. And the tablet would be at a workable distance, so they wouldn't have to move about much.
I may be way off with this example, but it certainly explains why "we" are opposed to the idea and many others are not. We are simply the wrong market demographic for this product! I believe that this product should be marketed to cruisers and touring bike owners, especially those who travel long distances on their bikes.
Good luck! I hope you find the support and market demand for your product, and that people use it responsibly.