That' s a big issue way out here too. Certain groups (ex. the Sierra [blank]) charge folks to go on hikes through public areas. If you ask hikers and public lands users who participate in non-extrative activities to at least pay the copnservation stamp, they' ll look at you funny.
When people start complaining about allowing hunting in an area, or why a certain agency listens more closely to hunters' concerns over non-hunting user groups; just say " that' s because the hunters pay for it (taxes, tags, stamps, user fees, Pittman-Robertson funds, etc.)" and see what happens. (if you evver do this I' d advise stepping back a bit).
I don' t mind if a group or person collects funds to share their knowledge about a public resource with interested folks. The irony is that many collect $$ w/o putting some of it back to the management agencies that take care of the resources. Several groups talk about building awareness as though they were doing something. Awareness is important, but awareness alone don' t build watering units or plant trees & food plots.