For some reason your comment shows grayed out to me, making me think it's been downvoted. I don't know why this would be downvoted. FWIW I've seen the same beh

For some reason your comment shows grayed out to me, making me think it's been downvoted. I don't know why this would be downvoted. FWIW I've seen the same behaviors you described in most developing economies where people don't seem to trust the larger system. I don't know if the end result is any better - food borne illnesses are still quite common despite these 'heuristics' (as you aptly named them), but there might be far more causes than just unclean veggies.