The reason why most people (the general audience) didn't like the movie is its CONFUSING! Especially at least 90% of the general audience didn't the source material.
I agree a lot with this. I have to wonder if some people went into Watchmen thinking it was going to be a standard superhero action fest and got instead a darker, R-rated deconstruction of heroes.
I really liked it when I saw it in the theater. It was visually stunning. I liked how all the heroes were rendered. The Bob Dylan opening was a haunting way to bring the audience into the alternate world of Watchmen. Snyder came probably as close as anyone to pulling off adapting the book. In fact I liked the movie's ending better than the comics. It felt much tighter putting the blame on Dr. Manhattan instead of this crazy alien invasion.
The only issue I had was switching out the Robert Redford joke for Ronald Reagan. I get it that people today might not have gotten it and Reagan was more familiar, but it made no sense. They should've kept the Redford joke and let people figure it out.
Other quibbles:
-I wish the film had used more 80s music and I'm not sure the fashion or look felt 80s enough for me.
-The makeup for Nixon was horrible. Though I did like the voice work for many of the McLauglin group people.
I do think WB erred by anticipating this film would be big, though maybe I thought it would've been bigger too back then. Looking back I'm not sure why I felt that way. While they were perhaps hoping for another Dark Knight, Watchmen has never had the kind of widespread popularity that Batman has.