Glad someone explained this better than I could. Halloween is essentially the only holiday in America where people come together just to make a good day for the kids. As long as there is no real community centers in America, events that foster community are essential for the working class. The closest holiday we have that's just a community celebration is St. Patrick's, and that's still centralized around parades and being 21+ instead of just the normal people around you. It's the one day of the year that Americans can knock on their neighbors door without any real concern.

Halloween is extremely consumerist because everything in America is consumerist. But Halloween being the most popular holiday in America is a function of worker's alienation from each other. Trunk or treat is a great example of this. People in rural areas with no real way to walk to each other's houses just pull up to a school parking lot with enough candy for kids to walk around 3-4 times. We buy $30 dollars worth of candy for the sole purpose of giving it to other people, we buy cheap yard decorations to make our community happy. It's the only American holiday that we're supposed to give to the greater community.