Frankly no matter how well a DM describes a scene, it simply can't evoke horror in D&D.
Why should I be afraid for character B being stalked by the things that go bump in the night while character C in the other game is smiting fiends back to hell.
Because they have a too high CR and might kill character B? So could an orc warlord with his great axe.
Dracula, Frankenstein, Wolfman and co. are not literal evil having taken form like even lowest dretch is.
Leaving aside the fact that, in 2e Ravenloft, as written, a paladin could
not walk around smiting fiends back to hell without calling enormous unwanted attention from the Dark Powers, I must say that I completely disagree with your initial premise.
Not only
can D&D do horror, I, in fact, inject at least a little horror into every game I run.
But, while the monsters are a tool for delivering horror, they absolutely are not the primary vehicle.
Instead, you need two things:
1: The Unknown. Don't
tell them what's out there,
show them. Some of it. Let
their imaginations fill in the details. Absolutely, never, ever, call a monster by a categorical name. The minute you do that, you have put a quantitative value on it, which is the Enemy of Unknown.
2: Tension. Put the PCs in a bad situation and keep making it worse. Don't let up. If the players care about success, they
will feel the tension. Of course, in order for this to work, you have to be fair--and make sure your players know it. Actively root for their success. But keep the tension building.
And truthfully, if you do both of those things, you don't even really need that much player buy-in. As long as you've established trust between DM and players, you still have everything you need. If, for example, a player cracks a joke (whether in- or out-of character) that resets the tension level, all you have to do is tighten the screw to compensate. Which you were going to do, anyway. Let them joke. Laugh with them, even. It won't improve their situation any.