I feel most people I've heard that criticized the control scheme just didn't have enough time with the demo, because if I had only played it once with each class (especially in the case of the Wizard), I would have walked away with a negative take on the controls, too. There will definitely be a learning curve and not just for skill interactions or class mechanics, but each skill had its own targeting or aiming mechanic and learning all of those will take time in figuring out different builds once we actually get our hands on the finished game. By the 10th playthrough the button placements were second nature and the game felt a lot more refined. Plenty of other content creators have weighed in on it already and the only thing I have to add to the discussion is that it took me about 5-6 playthroughs before I started getting a feel for them. One issue I see that has come up again and again about Immortal is the controls. I also wanted to touch briefly on the controls for Immortal. I like the idea of this approach as most end game builds in any ARPG are largely disconnected from its resource system, whereas in other styles of RPG resource mechanics play more into specific timing or rotation than what we've seen in other Diablo titles. There was some discussion with devs about maybe adding a function to certain skills that would reduce the cooldowns on other skills as a kind of 'generator' mechanic. The 'cooldown resource' overall felt okay once I had adapted to it. The flow of gameplay is quick-paced, faster than D2 while not as frantic as D3.

Personally, I found the game to be fun as the Monk and Barbarian, but the Wizard needed a lot of work. The feeling from people who had the chance to play the game at BlizzCon seemed largely positive, and demo exit poll discussions with the devs at the show were encouraging. There are some positives when it comes to Immortal. I feel there are some actual good points to Immortal and there are things we could be excited for, but there are obviously many issues to be concerned about as well. Since then, outright anger has condensed into solid criticisms and vitriolic comments have made way for thought out concerns. I know this article is coming late, being over a month since BlizzCon, but I felt that it was almost impossible to discuss Diablo: Immortal immediately following the announcement.

Diablo immortal fail crowd reaction