These numbers are enormous, and while some games can boast higher numbers (over twenty-seven million people play League of Legends every day), remember that World of Warcraft wasn't (and isn't) free. It requires a monthly subscription, which is a huge deterrent for its player count. Basically it meant that at its peak of twelve million monthly players, Blizzard Entertainment was raking in over one hundred and eighty million dollars every month at that time.
So, I don't think it comes as any surprise that a 'Warcraft' movie was hinted at for years upon years. I remember going to BlizzCon every year back then and thinking "Maybe they'll finally announce the movie this year!" and always being disappointed. But eventually, as I think it was inevitable, it did come. The movie, Warcraft, is roughly based on the story in the game of the same title. The movie adaptation is quite a few steps different from the original story, but I'm not surprised that sacrifices had to have been made to change the medium so drastically.
I, unfortunately, have never played any of the Warcraft trilogy, so I am only vaguely aware of the lore based on what I've been told from my brothers who have, and from the lore in the MMORPG, World of Warcraft. I think at this point so few people are familiar with the actual story that its best to look not at how different it is from its origin but to the quality of the movie in a vacuum. (This could be the most arguable thing I've ever said on this blog, but bear with me.)
I know a lot of people didn't like the movie. I think the general consensus is that the movie is 'alright'. The subplots are juggled back and forth like mad, and it can be extremely difficult to try to follow along (especially if you're not familiar with any lore). It has a lot going on and about a dozen characters are thrown at the audience twenty minutes in.
But, I personally probably like this movie more than the average person would. Its special effects are on point (I haven't heard any negative critiques about that specific aspect) and all of the characters involved are more or less believable. The orcs have an obviously different society from the humans, and I think that comes across very clearly in the film. My biggest problem with it is the fact that I preferred the orcs side of the story. I was always a little disappointed when it cut back to the humans because their characters were just a lot less interesting.
Overall, I think this movie sets a good foundation for the future. I don't mind if the movies aren't exactly true to the lore. The Marvel Cinematic Universe is a thing, after all. They aren't following the comics entirely, and its still working quite well. So we'll see where it goes. The movie was alright, but its greatest aspects weren't in the story. I think the next one will be better because it won't have to spend nearly as much time establishing the characters and whatnot.