In terms of stakes, this movie similar to Beauty and the Beast. Initially there's a conflict where Merida/Belle don't want to get married to somebody that's being forced on them, but the conflict evolves into a supernatural race against time to lift a curse. The main difference though is that Merida is more similar to Beast than she is to Belle. Merida, like Beast, is the origin of the curse, and like Beast it's necessary for her to grow and change as a person for it to be lifted. Despite her mother being cursed and the vague political threat in the background with the clansmen that her marriage is supposed to resolve, Merida hogs pretty much all the major plot points and character development.
In Beauty and the Beast, Bell and Beast are duo protagonists, but Merida doesn't really share the spotlight with anybody. Her mother comes close, there's the implication that she needs to understand her daughter more, but this is totally eclipsed by the urgency of the "lift the curse" plot, which again puts all the emphasis on Merida's actions. There's nothing for anybody else to really do but sit around and wait for her to get over herself.
That's really what the problem is, the whole movie just waiting for a teenage girl to get over herself.
