Horror buffs know this ISN'T that bad...
I've you rate movies like I do (and I think most people should) then you should only rank a film against it's peers. I would never say this is a good movie compared to things like The Godfather, or Wreck-It Ralph or Jurassic Park etc. But against other horror films? It's not that bad.
Sure the original Pinhead is missing, and it was filmed in 2 weeks, and on a 300k budget (which I thought they made use of VERY well), but at least it had what I've come to expect from Hellraiser films: gore, rough sex, and the puzzle box appropriately tied into the story. I felt Revelations at least honored the Hellraiser spirit.
If you're going to flame me for what I've said, ask yourself these questions first...Have I watched Mr Jingles? Have I watched The Graveyard? Have I watched Blood Reaper? Have I watched The Howling 3/7? I really could go on listing more horror films FAR worse than this one.
Regardless, if you answered 'no' to the above questions, I really don't think you have the basis for comparison to call this a bad horror movie.
"Well...I've seen enough. Come on Charlie, we're going home."