As I said, I might be wrong. But overall I strongly believe people, especially on forums like this, overhype the game to extremes. Don't get me wrong, I'm sure the game will sell well. just look at the EA. But I don't think it will reach that far outside the common rpg market. And that's ok. It's not a niche market.
Believe it or not, but yesterday I discovered that a friend of mine, a person that spends atleast 8hours a day gaming, and has done so the last 17 years, had never even heard about Baldur's Gate. or neverwinter, or icewind dale, or any similar crpgs. Because he simply don't like that genre. But you can be damned sure he keeps tag on every single little news he can find about up coming games that does interest him.
Your logic is sound, but I think your grouping of this game with the crpg genre although true in reality, is not exactly how this game is perceived. I can definitely see for example people who played dragon age inquisition and the Witcher 3 being drawn to this game much more than to any other crpg of its kind. People tend to underestimate the cinematic presentation on this forum, but I think it is important to draw people in. And I think the crowd of the Witcher 3/dragon age games are kinda hungry for a new game that is not isometric text based hardcore but doesn't compromise on other RPG elements of story and choice