Also, some kids are extremely shy or scared. My mom used to dress me in what she thought was cute and I'd feel very self-conscious. Then, we would walk passed people dressed as demons, vampires and zombies and I'd be extremely frightened because I had an older brother who tormented me by scaring me all the time. 

I remember taking my kids trick-or-treating and a guy passing out candy, asked a little Vietnamese boy where his costume was. The kid shrugged and the guy said , "No costume, no candy." 

We don't know what financial issues the kid's parents had, or if there is a cultural issue (recent immigrants who are allowing their child to participate in a holiday they don't celebrate in their native country). 

If you are practicing a holiday for the kids...celebrate for ALL the kids.