Well, their cause is not bad, just even. But it is not justified by the way they act. I say bad, they have since long abandoned their original belief to retake the Reach. Altough that may still be a primary goal, i think it is more about revange and hate against the Nords. Would they be content if they get the reach? I think not, murders against the nords would continue.

Even if the Nords are the ones who drove then to be bad, they are still themselves bad and if they do not prove otherwise I say they are bad. Seeing as they attack all who is not forsworn and not only nords as well.

Bad, as they attack indiscriminately. If they only attacked soldiers, it might be more defensible, but slaughtering civilians is just wrong.

Well the first problem is defining what's good and bad who draws a line in the sand and says thing on this side are good and things on that side are bad ?. Who has the right to draw such a line and where do they get that right from ?.

Don't try too hard to have a different opinion. It's pretty clear that they are villains.