Way more than 2% are going to say that their favorite part of Christmas is spending time with extended family. Others like the decorations, songs, and general festive atmosphere. I don’t think very many would say “celebrating the birth of Jesus”, but they’re not as materialistic as you claim.
Sure, holidays in general are commercialized over here (except for maybe Thanksgiving, which is really just about family and food and maybe football), but that doesn’t mean there’s anything intrinsically wrong with dressing up in costumes and getting candy.
In any given year, I see way more spidermen and princesses than ghosts. I think I usually went as an astronaut or alien of some kind.