Disappointment is one thing. Straight up hostility and toxicity, particularly hostility directed at the devs because you don't want a thing? That can fuck off. I do not understand how people are defending this attitude and the behavior of people like that of the guy at the panel.
I personally wasn't defending that kind of behavior as I know the decision to make the mobile game probably wasn't even their choice and it's unfair to them to take all the heat.
Surely they knew that this was coming though when they announce it to some of the most hardcore Blizzard and Diablo fans out there? This shouldn't have been at the end and probably not as an announcement at the opening ceremony period. It may have gone over better that way if it was announcement at a different time like with Diablo 3 for the Switch.