I honestly was hoping hoping it would be great, I mean Duncan Jones made some pretty amazing movies and in his interviews he seemed like he had a genuine love for the source material.

I kinda figured though, not because of the cast, but because of the source material itself and the direction they took.

The movie could have been done in two ways, super campy and funny (Sam Raimi would have been amazing) or a serious movie with some light elements (think Lord of the Rings). They seemed to have split the difference and that's never a great idea.

Imagine if they had done a movie franchise starting off with Arthas and his fall into darkness, the formation of the alliance to defeat him and finally their march onto Icecrown. It obviously could be seen as a rip off of LOTR but I can also see that being an interesting movie to watch.

The problems I saw with the trailers was honestly that there were too many characters, also seemed like there were multiple elements to the plot (Orcs trying to find a home, humans torn between helping them and afraid of them, threat of the legion etc.).

LoTR had a ton of plot elements too, but by focusing only on the hobbits (in the first book/movie), every character was slowly introduced, only in relation to how they interact with the hobbits. It was brilliant storytelling in the books and obviously the movies, audience had time to get to know each character and the plot was largely very simple. The only real plot for each character was either, how to protect the hobbits or how to get the ring to Mordor (obviously getting to the town was a part of this), that's it. This meant that the entire first movie could focus only on getting to know the characters themselves.