Changes in iOS 8.3 completely broke the engine we have been using for the last several years. To continue development would requiring licensing and learning a whole new engine, and the low potential earnings just doesn’t make it worthwhile.
Leaving behind the old, and embracing the new is the name of the game for the developer community. But when Apple breaks engines many small developer shops will break too.
As an aside, I often work and study at coffee shops in Silicon Valley and have noticed there seems to be less people using iPads. It might be that I’m at the wrong cafes, but let me tell you why I no longer use a tablet: I have a laptop for work-related things, and for everything else I have a large — 5.7 inches to be exact — smartphone. A tablet is not useful enough to carry around.