I acknowledge that the exhaustion factor with hyperactive toddlers could play a part. Maybe the parents felt that the woods was a safe environment to just let them run wild unattended. Sadly this is not at all true, you might as well put them in the paint and cleanser cabinet to make themselves a snack.
As for adults who thought they knew what they were eating - I do appreciate that concern. I have taken a number of 'newbies' out who wanted to learn about edible mushrooms, and the inability to tell one from another keeps coming up for awhile, not just the first day out.
I think in our culture at least, where mushroom foraging was not a tradition, people are unfamiliar with the specific details that make the difference in a mushroom. Where multiple characteristics have to be used, it's easy to make a mistake.
There is also a possibility of poisoning by careless picking in some cases. Winter chanterelles being small and brown and growing in high density groups are a case in point, because interlopers or imposters do turn up in the middle of these patches from time to time, which could be included in the pick by accident. Personally I always qc my mushrooms by spreading them out for inspection when I get home, and I encouraged others to always do so as well. In spite of being very safety conscious in the field I have at least once found a small mushroom in my pick that didn't belong - and I have found more than that in the pick of others.
I also take a lot of care in cleaning mushrooms before cooking, and would never just dump from the bag into the pot which sadly some people do. And I do the same with fresh veggies, pick through wash and spin before making a salad. Not all weeds are edible.