That's not what I am surprised about.
My opinion is that fishermen's behaviors (collectively) are generally going to be consistent throughout each river whether it is Stave, Campbell River, Vedder, Capilano, Squamish, etc. People who litter in one system are the same people who litter in others. People who abuse resources in one system are the same people who do so in others. I don't believe that anglers are specifically targetting Stave River for bad behavior. That's why if I were to buy a house near a river, I do expect fishermen to be on it and expect the typical behavior that goes along with it (which are not all bad. they are diverse) and it goes without saying that rivers closer to urban areas or have good access will probably have more anglers on them. So it brings up the possibility that the motives of these complaints may be similar to those complaints brought up by those who bought property near the nice beaches in Howe Sound where there are anglers. I don't really see anything out of the ordinary at Stave. Its not like people are camping overnight, lighting campfires, getting drunk, partying, group singing around camp etc.