I think the problem with Fury X is in some way HBM.
Why? AMD felt that, because the card has HBM, it needs to be the highest of high end, to target the 980Ti. However, its very difficult to make a card to target that level of performance. Not only that, but HBM's immaturity means that only 4GB of RAM is possible. Not that the amount really matters - we have seen that it still does amazingly well in 4K benchmarks. My point is that, not only is the performance slightly short of the 980Ti, but with the memory being smaller too, it means the Fury X is not as future proof.
I personally think they should have repeated the 4870. Made a card similar to the 290X, maybe a little more optimized if they can, with 4GB of HBM. Price it competitively, make it a card that can beat a 970 in all situations, and you will have hordes of fans. It would sell very well.
Very few people are going to buy the Fury X. The problem with aiming for a halo product like the 980 Ti, is that if you shoot and miss, you lose everything. Very few people will buy it, because it is not a convincing win.
If you're going to spend $650 on a graphics card, you want to know you are getting the best. The Fury X is not the best, so why spend $650 on it?