As a fan of Blizzard in the 90s, lol.
Diablo 2 came out in 2000. Starcraft 1 came out in 1998. Warcraft 3 came out in 2002.
"Where's my sequel to a 6 year old game!?"
Then you know it takes forever for Blizzard to go from announcement to game. If they announced D4 on Friday, it would be minimum two years before it released, maybe three. Diablo 3 took three years from announce to release. So that makes a nine to ten year gap, which is not all that inconsistent with the history.
That's the thing, this game is a mobile game tailored to the China market. They chose a partner so they could more easily tap into that market, and they tried to sell it to people that play Blizzard games on pimped out PCs. They should have handled this much differently. A titles screen and couple pieces of art would have been enough - tell the audiences "you know we take our time to get things right, so we don't have much to show today and can't answer many questions yet" and fans would have loved it. Immortal should have been revealed at Apple's iPad show a few weeks back, Apple would have loved that and it wouldn't have been an insult to the fans that paid a ton of money to go to a fan convention or got virtual tickets. It would have been more like "you also get this" and less "this is it, deal with it". Nobody likes to open their biggest box Christmas present and find out it just contains socks.