Fact is, adults now "celebrate" Hallowe'en more than the kids do, at least in the US. And no matter what the demographics say, adults still control more money than kids (and adults always bought for Hallowe'en anyway). So, if you've got the folks who have the money willing to celebrate, why not make it a selling season?

Of course, I do think they might hold off until at least the 20th of September....