Oh, the hate for Diablo Immortal came mainly because fans were hoping for a new installment in the Diablo series, and instead the "huge" Blizzcon announcement was a mobile game. Fans didn't even have to think about the negative connotations associated with mobile games. They were disappointed even before any of that was considered.
It ended up being a perfect example of how disconnected Blizzard is from its fan base.
Except we all knew that Diablo IV was highly likely to be announced later on -- as it turned out, the next year. Would I be annoyed if Diablo Immortal represented a shift in the entire franchise (away from its roots)? Probably, but I knew that it wasn't likely. It's just a mobile game meant to add to Blizzard's portfolio of games, and we'd eventually get the main entry in the franchise. It also helped that we had tales and rumors of turmoil with the Diablo IV development, which let us know that something
was in the works, and also likely why we didn't get to see it. Also, prior to that Blizzcon, Blizzard posted a slightly vague article about there being multiple Diablo projects in the works, but also that not all of them would be shown off at Blizzcon '18.
I mean... at least for me, there was plenty to make me not fret at all about Diablo Immortal and the eventual unveiling of Diablo IV. ...and I don't care if Diablo Immortal is a "reskin" with some tweaks, as long as it's fun and doesn't try to monetize me to hell.
Ultimately, I'm just waiting to see what actually ends up coming out. Although, on that note, it seemed fairly far along, so I'm kind of surprised that we haven't seen anything on it yet. But if the game ends up being an overly monetized slog of a game, I'll be glad to lambaste Blizzard over it just as I would give Nintendo flak over Mario Kart Tour.