This is sounding a little like the Transformers Defense, i.e. "Because this film is of this genre, you need to lower all expectations to zero."
I don't see why a "found footage" production has to have poor-to-nonexistent mythology or narrative. I enjoyed the way Blair Witch's mythology tied in to the actual film, and liked hearing all the weird theories and ARG stuff surrounding Cloverfield. I haven't seen The Last Broadcast, but it sounds like they at least put a little more work into mythology. It's not the equivalent of demanding a Shakespearean narrative arc out of GI JOE -- a solid story is not something that has to be thrown to the wind for the sake of genre (though admittedly realism might have to be tossed aside).
More to the point though, why even include the Ouija board and the demonologist and the website if there wasn't going to be any resolution to those threads? Is it just padding so they can justify a 90 minute theatrical release? Is it a tease?
Someone that takes Paranormal Acitivity more seriously might argue that there is something a little more intellectual going on --- that the whole movie is about teasing us with small-scale unelaborate scares and red herrings, and then denying us the payoffs we want as a means of commenting on the genre or on life itself. Or maybe the narrative taunts us in the same way that Micah taunts the demon, thereby increasing the audience's bloodlust in the same way that Micah increases the demon's bloodlust. The viewer becomes the villain (see also: Funny Games).
But your position is that this is a rollercoaster meant to defy analysis, critique, etc. So why are there these plot points leading nowhere? If it's a rollercoaster, then the red herrings are the equivalent of having a long, slow steep vertical climb that you think is going to end in a steep vertical drop.....but then concluding the track with nothing but a slow horizontal straightaway. If you want to streamline your rollercoaster, why not dispense with the teases and just give us more steep drops? I guess you could argue that budget is a concern, but having a limited budget strikes me as all the more reason to make your non-scare non-action sequences more compelling.