Why is this wrong or disgusting?

The tribes are allotted a percentage of the fish on the Skokomish and what they chose to do with them is not up to you. How is stripping a chum of it's eggs for resale and putting the carcass back in the system a bad thing? Is that worse than commercially harvesting a chum then having it turned it to cat food, or some other animal food product?

Are these even wild chums, or are they hatchery raised chums?

Rotting fish on the bank will eventually turn in to nutrients for the surrounding river and ecology. Trees will grow, the ground will be fertile and the baby fish will get fed.

If you think there's an over harvest issue, take it up with state and tribal fish managers. They obviously do not think that this is an issue.