What would happen if some satanic nuts decided to celebrate Jeffrey Dahmers murderers every year at a certain time by ritually killing and eating people? And what would happen if over the years more and more people joined in? And if after a thousand years or so it was considered quite fun to celebrate it. And after a while Christians join in and honor the day by having childrens parties on or near the day?
Would it be okay? Or would the original founders of the holiday be glad that their observance had made such an impact on society?
Are you equating childish rituals of gathering candy at someone's front door to the pagan rituals that started Halloween? Yeah, the beginnings of Halloween were evil and because of it's beginnings, there will always be those who chose to celebrate the day as it was then, but kids aren't thinking about that stuff.
What's so evil about trick or treating? All the years I did it as a kid, not once did I think of any evil that went along with that day ... only about all the goodies that I got. :o)