But that's just it... they don't.

The scenes they've lifted from Psycho (Sam and Marion; Marion, her boss, and lecherous client; getting pulled over by the State Trooper) have departed from the events of the film without adding anything new or interesting that would make the deviations from "canon" worthwhile; they're just doing bloodless, uninspired retreads of scenes the original did MUCH better. They should either leave those scenes out; have them mirror the scenes in Psycho more closely to at least partly preserve canon and, hell, just as a fun and interesting artistic exercise in and of itself (beat Gus van Sant at his own game, IOW); or do something wildly different, that brings enough new and interesting material to the table to justify taking a revisionist approach. As it stands, it doesn't feel like they're putting any effort into those scenes at all, but simply going through the motions because they seem to think that's what the audience expects.

At the end of the day, the marching orders of any prequel should be to respect the source material, not reinterpret it (or remain true only to the spirit of it) the way a remake would do. As discussed in dozens of other threads, there were certain liberties the producers of the show had to take, such as the modern setting and inclusion of characters not referenced in the film or novel. Those liberties have either added to the story or, at the very least, not taken away from it. The same can't be said of the lame Psycho retread scenes from the last episode.