They're not fighting for independence. Independence from what!?
All they do is sit around in huts, eating animals and slaughtering innocent civilians. They're not a structured society and their leaders are undead (briah-hearts).
They worship hagravens, who are essentially litches.
So, how are they fighting for independence?
They are fighting for independence from both the Imperial Government and the Stormcloaks because The Reach belongs to the Forsworn. Who are these other organizations that think they can just come in and tell us what to do.
Sounds a lot like Ulric and his Stormcloaks doesn't it?.
And there is no such thing as an innocent civilian in war. Imperial and Stormcloak spies is what they are.
And making fun of their gods? Like the Nords worshipping some dead guy makes any more sense. And don't even get me started on those make believe deities that the rest of Tamriel thinks exists. Ghosts and hogwash is what that is.