4. The Lack of Technique/Expertise
As I said in the point about the franchise being reductive above, the Paranormal Activity films are created with as minimal fuss or ornament as possible: they are comparatively cheap to make, casting little-knowns and unknowns, and setting out to get the maximum immediate response from the jumpy scares. There is no need to put more into them, because the type of audiences who go to see them now - at this stage in the franchise - know exactly what to expect, and actively seek that particular thrill. Unfortunately that strong market position means the film-makers don't have to attempt anything that pushes the boundaries - yes they'll look for newer ways to present the same sequences and thrills, as the fourth film did with its fascination with modern technology, but at the end of the day, the formula unfortunately limits how innovative anyone can be, without deviating too far from the source. You need only look at the problems of The Blair Witch 2 to see exactly why the Paranormal Activity team won't drop what they are currently doing, so they can only ever be commended for achieving anything within the precise constraints of the franchise. Henry Joost and Ariel Schulman actually should be commended for trying to do something different with the franchise for this fourth film, but it could only be successful to a point, and unfortunately for them, the critical response was never going to be astounded, apart from the odd few. But then, since when did this sort of film care about the critics?