I think you are on the money.  School children are taught early on that mankind is ruining the planet and eventually it dawns on the students that they are part of the problem by being alive - consuming resources, displacing other species, etc.  Every excursion into the "natural" world is prefaced with a discourse about "taking only pictures and leaving only footprints".  When a group comes to a park that includes a cobbled beach typical of this area, Seattle, more than half the time the leader will stop the group and draw their attention to the crunching sound.  "There are hundreds of barnacles and other little creatures being killed".  Can't even leave footprints.  It doesn't take too long for them to start feeling guilt.  (I tell my groups to wear their rattiest sneakers, don't dig in their heels when they walk and don't walk on the boulders but between them. The boulders are sometimes "snotty" with algae and landing on them is exquisitely painful.   

Many people feel that it is permissable to make up facts to support their rationale to restrict others in order to "protect the environment."  Kinda like "We're doing it for the children."  If the person confronting you sees what you are doing as depleting the resource or harming it somehow, he might say anything to support his position.  For instance, "Taking those shells keeps them from being recycled by the system and depletes the level of calcium that the other clams and snails need to make THEIR shells."  On the surface, that sounds good but most shells are buried, anyway and naturally become unavailable.  That person probably drove over miles of shell roadbed to get to the beach just to nag you.  I did a little quick math and estimate that a cubic meter of sea water here contains enough calcium to give >30,000 adult littleneck clams enough CaCO3 for a day's shell growth.  Here, with a 14'average tide change, each square meter of beach at mean low low water will be covered by more than 4 cubic meters of "new" water, or enough for 150,000 clams.  I really don't think we're depleting anything.

Another example is the hermit crab that is using a small fragment of a shell.  "That's evidence that harvesters and collectors have taken so many shells that he can't find a good one and has to just make do.  He probably won't survive with that little amount of protection."  As it turns out, the species that winds up with the fragment is a predator (Hairy Hermit Crab)and prefers the lightest one he can find.  Light armor wont slow him down.  The most obvious hermit, the Grainyhand, the intertidal beach is a grazer and it likes the Nucella lamelosa shells.  That shell is ponderous but the Hairy Hermit can't reach down into it far enough to pull him out.  My enlightening the class was not well received.

And on it goes.

Some people just like to exercise influence over others' lives and "Saving the Planet" is just another weapon. 

Sorry to rant but I wish that teachers would stick to teaching kids HOW to think, not WHAT to think.  They are too often wrong.