Posting without reading, because I notice no one has mentioned Silent Night, Deadly Night. It was in theaters for one week (late 1984), and did not go straight to video, since home video was in its infancy. Over time, after it did get on laserdisc and VHS, it developed somewhat of a cult following, with a series of sequels (in name only), but I still wouldn’t put it on par with Texas Chainsaw Massacre as far as return on investment.
Point is, at the time, critics were aghast. Siskel and Ebert denounced it* on their show. Teenagers, as I was at the time, got mad cred if they had seen it during that brief window. I have never seen it, so I can’t address the violence/scariness/gore, by itself or vis-a-vis Friday the 13th and Elm Street. I do remember the gist of the outrage being that a killer Santa was just going way. too. far. Killer clowns, sure, but a killer Santa was un-American! Also, the Wiki article tells me that the movie doesn’t give the Catholic Church a great character**, so that was also a factor.
I think I can see a subconscious trigger, too. Jason wears a hockey mask; Michael Myers wears a blank-face mask. Freddy is burned, and a clown is wearing full-face makeup. So the victims don’t really see their killer. But Santa is a familiar face, smiling and grandfatherly. He’s safe, even to adults. Seeing Santa snarling instead of smiling, just before he horribly murders someone…well, that hits the audience too much where they live.
*Yeah, they also denounced the first Police Academy movie, and look how many sequels and $$$ that engendered.
**Remember the Satanic Panic? Remember how a lot of the signs that Your Teenager May Be Possessed were also signs of depression, or ADD/ADHD, or just signs of being a teenager? And so many parents chose to keep Satan at bay by pushing their kids into church activities. I wonder how many of those children were “helped” right into the hands of a predator.