Unless someone with inside info chimes in, it's going to be hard to do much more than speculate about how Nikon's sport optics division is actually doing, or what its strategy might be. Nikon made binoculars earlier than they did cameras/lenses, and their history in this area rivals anyone's. That said, it seems to me that Nikon has likely had more success competing in the mid to upper mid range, eg. with its 8x30 A and E series binoculars and now with the Monarchs, than at the very top end. Focusing their undoubted expertise on the sub-alpha (Monarch HG) and below categories, which almost certainly sell in much greater numbers, may very well make better business sense than competing in the crowded and competitive alpha market. I certainly felt the Monarch HG 10x42 I tried was a very capable birding binocular and, although the view through the EDG was
superior in a number of aesthetic respects, I'd be hard pressed to say that the latter was truly superior at the basic job of bird identification and observation, and certainly not in proportion to the price differential between the two.
Regarding the EDGs themselves compared to other alphas: though a superb and well-executed product deserving to be ranked in the top tier, which I would use with great pleasure if one were available, my own feeling is that I was going to buy an alpha for myself and could afford only one, I would personally rather have the sharpness to the very edge of the Swarovision, the wide field of the Zeiss SF, or maybe the deep saturated colours of the Noctivid etc. The EDG range has great qualities (glare resistance etc. as noted by Tobias), and with preferences in binoculars being so individual, I could not quibble with those for whom the EDG is their favourite. I readily admit that my appreciation of top-tier binoculars may not be refined enough to appreciate its finer points. But there is something I just like better about the other alphas compared to the image I see through the EDG, excellent though it is. They each have something that immediately grabs you and wows you, whereas the qualities of the EDG, while of considerable merit in themselves, are probably more subtle and not as immediately apparent.