Firstly, he's made it quite clear that he's all for the upcoming remakes of his classic movies Hellraiser and Candyman, provided there's a good story to be told, and that something different and interesting will be done to make them worthwhile. He inferred that he'd rather see a quality remake than a sequel which does a shoddy job of adding to the franchise. A while back, he had officially given his blessing to the Hellraiser remake in particular, but the directors he had approved have since left the project.
Also, Barker made some strong remarks with regard to the recent trend of trimming down horror flicks in order to get a more audience-friendly PG-13 rating:
"It’s one of the most disgusting developments in the last few years; the whole notion of a PG-13 horror movie to me is a contradiction in terms. It’s like having a triple-X Disney picture. It doesn’t work... Wes [Craven] says that ‘When you go into a horror movie, you need to feel that you’re in the hands of a madman.’ Now what madman makes a PG-13 picture, right? Your horror-movie madman… doesn’t neaten up all the edges and make it all nice for mommy. [Studios] do it because they want to bring in younger audiences and make more money. But they don’t make better movies."
While I agree with Barker primarily, there has to be a distinction made here. In recent cases in which this phenomenon has occurred (such as Prom Night), you're talking about a situation in which studios have taken material that is clearly meant to be of an rated-R caliber and diluted its effectiveness by forcing it into a PG-13 pigeonhole. From a creative and artistic standpoint, that's clearly a disastrous development. However, that said, I don't agree that there can be no such thing as a great PG-13 rated horror movie. In fact, I think that's kind of ridiculous.
There certainly can be excellent horror movies rated PG-13 (and even milder!)--they're just different types of horror movies. Not the kind in which excessive body parts--both internal and external--are on plentiful display. But there are movies which can fully accomplish what they need to, and be effective, without exceeding the MPAA's guidelines for PG-13. For example, movies like The Others, The Ring, The Exorcism of Emily Rose and The Lady in White were all very good, and all rated PG-13. But to be clear, none of them were "trying to be R."
For that matter, what about every single great horror movie made before 1965, when filmmakers were unable to make movies of an R-rated type? Are we saying none of them are effective, none of them have the power to disturb us? Psycho would certainly be rated PG-13 if it were made today, maybe even PG--do we accuse Hitchcock of "neatening up the edges"? Granted, he didn't have the option of making his movie any more graphically violent, but would that really have made it any better than it is? Heck, Universal gems like Frankenstein and The Wolf Man would probably earn a G rating today. For my money, Nosferatu is a more powerful horror movie than many rated-R horror movies I've seen.
So I guess my point is, filmmakers should not be asked to reign in their vision in order to fit a PG-13 rating--but at the same time, we shouldn't broadly proclaim that it's impossible to make a PG-13 horror film that isn't well worth seeing.