Maybe "terrible" is a little harsh, but it wasn't good. Have you been watching The Killing this season? [SPOILER WARNING!!] The first few episodes of its debut season were all kinds of fantastic: an atmospheric, anti-procedural slow-burn, with that amazing actress from Big Love (Mireille Enos -- I'm still haunted by visions of Kathy Marquart's fatal braid-in-car-door encounter) brooding up the screen.
Then the show got a little annoying. I'm actually okay with the idea of not knowing who killed Rosie Larson until the finale. In some ways, it's an interesting experiment in measuring expectations. But we didn't actually find out who killed Rosie in the finale! Fail! And, for that matter, did there have to be so many red herrings? I think the idea was that in a police investigation, there would be lots of false leads, persons of interest who turned out to be innocent, and "clues" that would turn out to not be connected to the crime. From a deconstructive standpoint, I like that the show attempted to depart from the Law & Order cop show formula that gets so tired, but from a narrative standpoint, the story turned out to be just a jumbled bag of annoyances ranging from the slightly irritating (Mr Ahmed was merely helping a teenage girl escape an arranged marriage? Huh?) to the straight-up WTH?? (we learn about "Beau Soleil" ELEVEN EPISODES INTO A THIRTEEN EPISODE SEASON?! Girl, please!).
It shouldn't have been a shock that the finale was so lame, then, but the early promise of the show made me want to hope that the show knew where it was going. After the finale, I'm feeling a little misled. (E.g.: Richmond killed Rosie -- no wait, maybe he didn't -- wait, did he? -- now I don't care!) Even if Richmond was the killer, why did Linden tell him they were onto him? And for that matter, why did Richmond have his computer open (with audible alerts!) to the email account with his killer misnomer? Andy Greenwald at Vulture expresses my finale frustration the best (and most dramatically): "But the finale was just the last in a long, frustrating, and soggy line of cheap fake-outs, preposterous 180s, and colossal storytelling disappointments. By last night’s episode, we were Rosie Larsen: huddled, miserable in the dark woods waiting for the killer to reveal himself. And, unlike Rosie, we were denied even that."
The list of plot holes and poor storytelling devices has been discussed better and at length elsewhere, so I won't go on. The thing that I found the most annoying about the finale was that the show has a lot of great things going on for it (you know, atmosphere, rain, creepiness, Mireille Enos and Joel Kinnaman), but it squandered its potential with gimmicky, red herring crap that belongs on lesser shows on lesser networks. The finale did nothing to bring together all the missing and broken pieces of the story that we were led, as viewers, to believe were important. And, frankly, at the end of the day, a show that centers on solving a murder needs to solve the murder.