This has been discussed before. Someone can correct me if I am wrong, but I believe the primary problem with banning non-tribal commercial nets is the concept of "foregone opportunity". Basically the treaty tribes can take any share of the catchable fish (any fish above that required for escapement) that the non-tribals don't. So any reduction in commercial fishing will likely lead to an increase in the tribal take and no/little reduction in the number of net caught fish. Banning netting essentially becomes a big boon for the treaty tribes. The states you listed above don't have treaties that guarantee the tribes 50% of the fish. A great example of the tragedy of the commons.