Yup, that's the group I am referring to as well.
Before I say anything more, I want to say that I have no issues sharing a bit of bait with a newbie, passing on a hot fly, in parting a bit of knowledge where I can, heck, I have even passed off a $1000 rod and reel to a total stranger so he could land a fish...bottom line, I don't mind pointing a person in the right direction or helping them out.
I have talked with a couple of these guys...they aren't interested in learning, they don't care about what they are doing. Because of this, I have no issue going after them verbally when I see them snagging, mistreating fish, etc. I recommend that everyone do the same.
To be clear: try to help educate an individual if they are making mistakes but if they are unwilling to learn, develop, and change then give em S***, call DFO in front of them, make sure they don't feel comfortable continuing to do what they are doing. Sooner or later they'll get them message.