There's a ton to be said here but having looked into what people are claiming and are angry about this is a prime case of the gamer outrage cycle if I've seen one. Maybe the best example of it since No Man's Sky.

The short version as far as I can tell is Blizzard announced reforged with a short list of features. They got a lot of blowback from people about changing the game too much from what it was and so they changed paths sometime in the two years of development from announcement to release to keep the game close to what WC3 was. So they're getting blasted for trying to listen to feedback they received.

So the game wasn't what some people were expecting and it upset them (because there aren't more important things to get mad about.)

Sensing blood in the water no-talent assclown rageclick whores like Bellular and Angryjoe etc... immediately went to work getting the YouTube hate machine fired up and now here we are.