Most people complaining about the game are just suffering from buyers remorse because they created an illusion that they were buying a different game other than a RTS game.
The reality is very simple, people who play WoW don’t have what it takes to play competitive ladder games like WC3 or StarCraft. They are used to “collecting mounts and reading text” games, not to be tested against another person in a online match, which is what this is game about.
They wanted a campaign single player type of game, they wanted to read text and slay NPCs and there’s absolutely nothing wrong with that. But that’s not what WC3 is about.
WC3’s core game modes are 1v1 ladder, FFA, and online custom games. That’s 99% of what the game is about and it is completely different than the WoW gameplay these people are used to. WoW is not a competitive game, it’s a “get lost in the story and do repetitive tasks” game.
WC3 was announced in the worst Blizzcon of all time and end up getting the attention of a public that simply wouldn’t enjoy it’s gameplay, maybe because there was nothing else of value in 2018’s Blizzcon, maybe for other reasons.
But that doesn’t mean Blizzard can’t cater to the WoW players and work on new official campaigns and release them as DLCs. In fact it would only make sense that they would do it.
But they are not going to do it. At least not right now. The game’s development is really really late. The beta should have been here months ago. It probably should have been released already. If they announce they’ll “bring new extra campaigns to WC3 reforged” before even having finished the game people will be upset. Rightfully so.
But after the launch, after all the necessary patch fixes to the game that will inevitably be needed over the next 3~6 months, I bet they will be adding the content WoW players and other casual Blizzard “fans” (don’t be fan of a company, it’s lame) are looking for.