well, it’s quite simple, technology is still too limited, products would be too bulky for example, and it’s still too hard to program an A.I., on the bright side though, we’re seeing an technological revolution in size right now, processors are getting smaller, for instance, what really rocked my world was the via itx pico, that’s right, it’s around the size of a playing card… so technology is evolving rapidly, we’re just too busy to notice ;)