To some extent, I would imagine, this is due to a desire to avoid complaints from religious nut-jobs who think Halloween is about worshiping evil. (In the world of government schooling, everyone has veto-power. Hence the bland tediousness of the product they dispense.)
I think, however, that this is also part of a wider trend, to take the fright out of Halloween. This of course destroys the whole point of it, which is to be frightening. I see this trend as in interaction between two of the most repellent aspects of our culture today: our cowardly yearning to eliminate all causes of fear and anxiety, and our sentimental, diaper-sniffing worship of children. Together they have produced many results, including the virtual extinction of chemistry sets, the near-impossibility of kids wandering off and playing without the supervision of an adult who maintains a play-date calendar, the doomed efforts of many educated Americans to turn their boys into girls, and -- over many years -- the gradual erosion of the spirit of Halloween.
The universe is a dangerous place and everything is bad for you. Even if we have a rational response to objective occasions for fear, there is still the subjective one of remaining fears themselves. Coping with fear is something we need to learn early.
The Halloween approach to fear is, not to run away from it and censor those who remind you of it, but to confront it and master it. Halloween is when kids get to be scary. A scary kid is not a scared kid. Being scary and grossing your friends out is empowering. Also, pretending to be the thing you fear tends to demystify it. Familiarity breeds not fear but contempt.
In a world where people are continually trying to manipulate you through your fears, turning fear into a game can actually be liberating. I think Halloween is good for kids and should be bigger and scarier than it already is.
(Hat tip to Uncle Eddie for the vintage postcard illustration.)