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greengeez and others, you are right – in your own way. But, in my opinion, the root of the problem is that you initially expected something different from the game.
I myself am not thrilled with the anime-style elves with half-meter-long ears, Ents that resemble overgrown, bark-covered troll-shamans from Warcraft 3, and dwarves that seem to have come from Disciples. But the thing is that... today, they have to be like that! If in those "good old" days, when the third installment was being created, elves and dwarves were still somehow associated with the Might & Magic universe or the unforgettable Tolkien, now they are "those guys from Lineage and WoW"! Hence, the change in the game's setting and the banal plot – although, honestly, where does an original plot come from in a computer fantasy strategy game? The story of saving the world from a demonic apocalypse in one form or another has been exploited throughout the history of computer games, not just strategies, by the way (haha, even the first Doom is about that). Besides, in the age of multiplayer online battles, the function of the Campaign in a game is reduced to introducing the player to the types of units. Few people buy games for the plot – so why spend money on it, especially when you have to solve the not-so-simple task of balancing a huge number of game mechanics? This is bad, but – that's life. So, I wouldn't rush to accuse the developers of shoddy work – it's just following the established laws of the industry, starting with the elements of the plot and design and ending with Blizzard's sales strategy. On the contrary, I would shake the hands of the game creators for preserving everything that could be preserved and for the generally successful, in my opinion, development of the gameplay.
Well, and finally, Heroes 5 has another feature of modern games – it is an excellent platform for creating your own modifications. So, there is hope for the emergence of user-created Campaigns with a plot, and possibly even with their own graphics. It's up to you, modders!