I tend to do what @bouteloua does when I come across these photos, and make at least one comment explaining to them that iNat is not a general mapping tool. Something like anecdata.org is more likely more appropriate. I do think these “observations” should be discouraged.
@kiwifergus all photo of an observation should have the subject organism in the photo. Right now there’s no good way to distinguish environmental photos from subject photos. I would propose that, to deal with this situation, iNat comes up with a way for a user to designate some photos as environmental photos.