You don't hype a PC crowd up for a Microtransation riddled mobile game. Actually, you don't hype any crowd up over a mobile game. Then, they choose to use Blizzcon to announce that? For the Diablo crowd, that's the hype they get?
Why couldn't they tease D4, a new expansion and then throw in D3 re-skin? Literally not that hard to please people and make money nowadays. They brought this disaster on themselves and for them to know this would've happened ahead of time, is on them entirely.