Warcraft, The Movie. Why a flop???

Today watched the Warcraft movie and I see in Wikipedia and many other places negative critics. However I was with a guy who never played WoW and both of us enjoyed this movie. Just as was the case with the all praised Star Wars 7, my personal opinion is completely opposite of what the critics said. SW7 was big disappointment for me, but somehow almost all of the critics rated it highly. Now about the Warcraft movie, I am not sure what makes it a flop, so I'd recommend see for yourself and don't pay too much attention to clueless critics.