I think the problem with the UP system was that it THRIVES in macro and close up imaging, even more so than the newest and best sensors out there. The issue came when you were shooting anything outside 10-20 feet. The larger pixels captured the light beautifully, but there were zero details outside that short range. For example, shoot that flowery image at 12 inches, but then go back and shoot it again at 12 feet. The 12" image will look DSLR quality, but the distance shot will look point and shoot at best.
My Lumia 925 shot gorgeous images from the macro range out to an infinity focal length. The 8MP power of the 925 wasn't that much better than the 4UP of the M8, but the processing was just better. That said, I've taken some AMAZING shots with my M8 (and the M7 Android as well) and agree that the camera really gets a bum wrap.