Why dilute the detective story with the personal relationship plotlines?
The Carey Mulligan (always first-rate) plot thread was the thrust of the season and the most compelling. The politician's domestic problems with his 2-dimensional f'd -up wife was exhausted, pointless. Not just uninteresting - what did it have to do with the rest of the story? Same with the lesbian minister's "struggle" deciding to stay with her much younger, in-need-of-papers lover or caving to her hypocritical bishop.
If there's a season 2, I hope they just focus on Carey Mulligan. And glad they presented her female DI character as another sharp, overworked cop in the mold of other rule-breaking police like Harry Bosch, and didn't make an issue of her gender.