I think a lot of people are upset because mobile games are...simplistic. They're not the full fledged experience you expect on a console. Touch controls simply don't work for a lot of games. I think there's also the negative connotation that a mobile game will be riddled with gatcha mechanics and a pay to win infrastructure designed to force players to part with their money if they want to play the game.

And I think all of those concerns are very, very valid. I played Heroes of Incredible Tales, I played the Injustice, Tekken, and Mortal Kombat mobile games. I know how these things turn out. It doesn't end well for the publisher. And if Blizzard takes a similar path, they're going to find themselves in a lot of trouble. They struck gold with Hearthstone (perhaps literally), but that doesn't mean that they can do it again.