I think the biggest problem with this season is that the setting is too well known to viewers. Corruption in LA? Been there, done that. Chinatown, LA Confidential, Mulholland Falls, Training Day, Dark Blue, etc.
Season 1 gave us a mystical death cult in Louisiana. It's far less trodden territory.
That said, i'm still enjoying season 2. I just understand why some people aren't.
I'll also say that the worst thing that ever happened to True Detective: Season 2 is True Detective: Season 1. It was a very hard act to follow.
I agree with your thoughts. The first season was always going to be nearly impossible to beat, and then to pick a subject like corruption in LA, they weren't going to beat it. That said the characters have been great and the acting has been good, But there is a bit too much going on and some loose plot points. Considering there are two episodes left we are going to have to go a hell of a long way toward getting this wrapped up.
Just to float out into some speculation. You wonder if the team won't be able to find enough to pin it on anyone, and since because of this they take it outside of the law to finish what they started.