Emma Frost, though pretty lacking in depth, was better than the other villains and thus missed in the second half, especially as it was suggested she could break out but didn't.
Why can't the civil rights story not happen in the sequels? Couldn't they just pick up the next day in '62 and have the mutant civil rights issues/real world civil rights issues storyline continue?
It's too much of a distortion to overlook it and helps make Xavier seem excessively lightweight, especially when the film puts in archival footage of other news. It could have easily been added at least with dialogue.