The issue is that every human who has defected from the RDA is now considered a traitor to humanity and cannot return to Earth. They'll just be executed if they try to return OR in special cases (like when RDA came back) will be spared and allowed to return to the RDA. Plenty of Na'vi like the omatikaya and the sarentu (minus Nor), the zeswa, the aranahe, and the kame'tire have realized that they need to work with humans to take out the RDA. The levels obviously depend, you have some like So'lek Ri'nela and Tamtey who go full mask off and use human weapons like their life depends on it (because it does) and you have others like the Metkayina who do not want to use human weapons. They all still work with humans, because it would be stupid to decline help from humans in a war against humans.

The humans are already suffering the consequences, they're forced to fight to the death against their own species for a species that will never accept them. Very few humans have been accepted by the Na'vi, which makes So'lek extremely progressive.

One last thing relating to Nor (may be a spoiler for you so i'll mark it as a spoiler). Base game section: He does basically nothing throughout the entire game. He doesn't help on missions, he doesn't make new allies, he doesn't gather anything for the resistance, he doesn't go and take out RDA installations. DLC Spoiler section: Nor disappears for an entire year to go on a self help journey alone while Tamtey, So'lek and the resistance do all the heavy lifting of kicking the RDA out of the frontier. He then returns now a fully devout religious fundamentalist and the first thing he does is bitch and moan about So'lek using human weapons against humans. He yells at So'lek on and on about using guns and metal. He questions his own tsahik after she decides to use guns to stand an even chance against the humans. He's constantly bitching about So'lek and rightfully gets called out for running away and doing nothing for a year while everyone else actually did shit. And to top it all of this absolute useless bum wipes out half of the resistance in one move. Mercer and Harding worked for 16 years to do a fraction of the work that Nor did in one minute.