Well, it makes sense that we haven't seen much in the way of singleplayer D&D games in recent years, given their attempt at turning the system into an MMO with 4th Edition.
Neverwinter Online turned out to be hollow - much like the system upon which it's based.
I don't know 5th Edition very well, but I can't believe it's actually worse than 4th Edition.
If they had half a brain, they'd get a hold of a decent team with the means to get the job done and give them the freedom to create a proper game. I have absolutely no doubt the system remains popular enough for even a half-assed game to be a reasonable success.
SCL would seem to be the ideal test of this theory - as it has half-assed written all over it.