I don't think it was as bad as everyone else. I only started watching the show in January, but watch 5-8 episodes a week and there have been some really lame, roll your eye moments. I think it's just because it's the worst episode in awhile you guys and gals are being overly hard on it.
It wasn't bad if you like a show whose hero is a grown-up Shaggy Rogers. I actually liked the scene where Castle and Beckett talked about their respective views on belief; there was some beautiful writing there. I just object to the way the show has retconned Castle into something he wasn't before, even to the point of directly contradicting past episodes where he admitted he only pretended to buy into the fanciful theories. They've taken something that was originally just a minor quirk of his sense of humor and blown it up into his defining feature as a character. I miss the version of the show that was about a mystery novelist, rather than the live-action Scooby-Doo
series it seems to be turning into lately. I miss the version of the show where the cases were distinctive because of their elaborate, clever twists and turns rather than because of the supernatural hoax of the week or the vast conspiracies that have now engulfed both Beckett's and Castle's backstories.