I'm only half watching; doing sudoku whilst my wife watches SO I'm not really paying attention BUT...
...PS has changed. This change hasn't been explained. How is he motivated? He's no longer a serial killer and I don't get where he's at at the moment. We're to belief he enjoys causing and watching pain. But he kind of just skulks around, looking moody and being secretive.
There's a big dark secret being dangled, his dark world, that will presumably explain why he hasn't killed RS. Why he's developed an interest in Scully. Why he's spending his time grooming (an unbelievably) obsessed, silly teenager. At the moment, it doesn't add up for me and there's been insufficient tension (other than an illusory, faux and purported) to maintain my interest.
Why didn't they pull PS? Question him as a 'person of interest'? They have video footage of him breaking into Scully's hotel room, pull him over that. They could have had a face-to-face interview scene; teasing, ambigous, I know that you know, I know that you know that I know. Done before, yes, but a chance for actors to shine and always interesting.
I reckon they've had to impose a new trajectory after season 1 and they can't quite make it stick. Or they've no idea where they're going. Or, as succinctly stated earlier, they're stringing it out. There are some good performances, and it's well shot, but sadly the whole thing just doesn't stack up for me.