The DSLR market is shrinking, simply because everyone who wants one already has one and there are no compelling reasons to upgrade. There was a golden period of a few years where if you wanted a decent camera a DSLR was the best option, so the market expanded quickly. Those days are over.

Adding the features identified in the post would cure the "no reason to upgrade" problem, at least temporarily. But the market for serious cameras is pretty much fixed and easily saturated.