Which it probably didn't. Haunted tombstones aren't known for telling people to enjoy themselves. It's like a guillotine reminding you to floss. They don't care. They're being sarcastic. I'm sure there was a talking guillotine at the drugstore, and it said something like "don't lose your head over Halloween mwah hahahahaha" because we all know that one of the predominate characteristics of the damned is an inability to avoid puns.
There also was a cackling candy dish, because fiends supposedly cackle. Why? What's so funny there in the afterlife? Want to share with the rest of the class? We just accept it, just as the image of haunted houses is permanently fixed in the Victorian era. Oh, maybe in 100 years kids will use abandoned suburban bungalows for the standard haunted house, and ghouls will shout "I am the ghost of Chinese drywall class-action suits!" but for now we're stuck with the same old stereotypes.
Which is fine, I suppose, but when it starts in September you tire of festive death. It's morbid but cheerful, like working in a My Little Pony glue factory. In my bygone youth the Ben Franklin put out stinky plastic masks and costumes ("Now 50% less flammable") and paper skeletons about a week before Halloween, and a kid could work up some anticipation. Now it's a six-week smear, and the actual event is an anticlimax, like Christmas would be if you spent the preceding 35 days opening presents. It would be nice if they could limit Halloween to the last half of October. As for what they'd put in the seasonal aisle, I don't care. Invent a new holiday! Fall Happiness Interval!
But then I'd complain when scarecrows showed up in the seasonal aisle in August. Oh, never mind.