Hunting the way conscientious hunters describe it relies on a lot of written and unwritten rules-- be sure of the species, wait until you can get a killing shot, leave no trace, respect for the land you’re driving/hiking through-- that I’m sure are harder to hold to in bigger more competitive groups. They can make and enforce a whole list of detailed rules, or they can ban the type of event where people have a harder time exercising their own restraint.

It seems to imply it’s mostly related to competitive hunting of coyotes, rabbits and squirrels and that the competition is the problem more than what and how they hunt?

Now, I don’t know much about these specific contests, but conceptually, I fail to see a real problem with competitiveness, assuming whoever is doing the hunting first abides by the other laws, hunting seasons, bag limits, safety, etc.

A cursory search about Oregon suggests that coyote hunting is open season all year, no bag limit.
For squirrels, it depends on the exact kind, but the article is really about unprotected mammals, likely classified as such due to their abundance and in some cases outright nuisance.

Unprotected mammals include coyote, cottontail rabbits, black-tailed jackrabbit, opossum, nutria, California ground squirrel, and Belding’s ground squirrels.

idk, either there’s a bag limit or there’s not?