Blizzard's fall is well documented and obvious, but I'll push back on that statement. Starcraft: Remastered is recent evidence of the contrary. They did that damn-near perfectly. Didn't change the gameplay of the game and just added a lot of modern features and functionality around it. It was quite well done.
With that said, do you not have a phone?
Chances are, the only reason Activision kept their foul hands out of it is because of the nature of that game. They *cant* mess with that series too much without it totally collapsing, and they're aware of that. Even if they'd only be messing with the first game instead of the second, that's a really big risk for them. The ridiculously competitive nature of the game forces them to keep away from it in order not to leave a stain on the series that could damage it's current status. Not to mention that even despite the fact that there hasnt been a new game in that series in ages, it still makes them a fortune simply due to the e-sports aspect, which is the other half of why they cant touch it. That game's popularity is massive, particularly in Korea. Player outrage at things like lootboxes is common, but usually it's... lazy. They get "angry" and buy the damn games anyway, the damn fools. I suspect though that if it happened with THAT series, the fanbase would utterly flip out in a way that's rarely seen. Activision is incredibly shady, but they arent stupid.
Diablo, however, produces no such restrictions. It is a non-competitive game that specifically contains an element of addiction built into it's gameplay loop (as in the rest of that genre). There's no e-sports aspect of it either. They already showed what they're willing to do with the series when they attempted their ill-fated "auction house" with the third game, and that was BEFORE Blizzard became fully corrupted. They didnt even hesitate on that one, and only backed off when it became clear that they had no choice. Players didnt give in as easily back then, but that's changed. If they tried it again, it probably wouldnt be removed this time.
This is also why they're willing to make an obvious cash-grab of a mobile game based on it... Activision is in full greed mode with that one and they have no problems with it. They'll get away with it, too.
What absolute jerks they are.
A shame, really. Blizzard was legendary for a reason.
I wonder which studio will fall next?