I agree on that one for sure, a lot of religion seems to add in on Halloween thinking there's some sort of hidden evil that is out to taint the innocent. Perhaps even with that mother and the girl, unfortunately it came into play with me personally back when I was trick-or-treating. My mom always had these rules about "demonic" costumes because it would be "supporting Satan" so me and my siblings weren't allowed any sort of "scary" costumes and she held these judgments against people just for participating in harmless deviant behavior like scaring people. I still think it was a severe disappointment and greatly hindered much of the excitement because as the mother with the young girl my mother would have acted in the same way even if I did enjoy it just because she wanted to force her opinion.
And that is why I have a good laugh each time Halloween falls on a Sunday (like this year). Because those who do believe that Halloween is the Devil's holiday will be even more "frantic" about it when it's on the day that they go to church, at least, that's m guess.
But originally, Halloween was a day to celebrate those who have passed away. There's nothing evil about that, in my opinion. It's just like visiting a loved ones grave but apparently some people think there's a substantial difference. *shakes head*
Anyways, there's nothing wrong with being something scary. It doesn't mean you're evil. lol.