Well, our church is one of the guilty ones. I think the idea behind it is to provide a safer, wholesome alternative for the neighborhood kids. Our church isn't in the nicest area of town, and I would hate to think of some of these kids going door to door around that area. I don't personally care if my kids get candy or not, or whether or not they get to dress up. Our pastor does stay consistent with the wholesome theme, and stipulates no scary, bloody, gory or evil costumes.
I realize there are cynics (like you, obviously

), but it really was done with the community in mind. Our kids never participated in Halloween until our church launched Trunks of Treats (or whatever it's called--I can't ever get it straight), so we didn't do it for them. Other parents who did participate in Halloween now complain because they want to take their kids to other neighborhoods. Others opt out altogether. Those who stay in the parking lot with their trunks up and hand out candy ARE the ones who are interested in interacting with the neighborhood. In fact, most of them are older people who don't even have children at home.
Personally, Halloween is my LEAST favorite holiday. It doesn't even belong in the "least favorite" list because I don't like it at all. I don't see anything Christian about it whatsoever. However, I don't think it's right to refuse to hand out candy to kids, either. I don't think they "get" that it's a principled thing, so what's the point? They just think it's mean. The only people who get the statement are other Christians. Are they the ones to whom we're supposed to be making "principled statements?" Other Christians?
Whether or not we participate in Trunks of Treats, we have always handed out candy from our door. If someone knocks and asks, they are going to receive, to the best of my ability. It doesn't matter to me if it's Halloween or any other day.
To me, this is no different than my Dad's behavior around Christmas when I was growing up. He was staunchly opposed to Christmas. Wow, talk about a Scrooge. Hum a Christmas song and you'd get a lecture a mile long.

However, he also tried to make sure that we did something as a family during the Christmas holiday. We'd go to Silver Dollar City or Eureka Springs, AR, or SOMETHING. IMO it's okay to try to offer alternatives so your kids don't feel left out or resentful. I can tell you, there were a couple of things that happened because of Christmas when I was growing up that I did resent. My Dad overreacted, and it really was NOT that big of a deal. Unless someone is going to end up in hell over it, I say live and let live.