first I want to say that if you see any spoilers for a show, it's kind of your fault for looking at reviews before watching it.
I'll admit, season 1 isn't one of the greatest plots in anime history. Not because it's a demon x anti-demon organization redemption plot. But because of season 2. It was totally unclear and choppy as to where in time the show took place. I started watching with full confidence that these are the events after season 1, where Rin and Yukio destroy the gehenna gate. That is until I noticed Izumi and Rin having that "why would I be afraid of you?" conversation again. Word for word on the train ride instead of the hallway they originally had it in. I don't know if the show forgot that they already had this conversation or if all these arcs between characters happened at all. But the show never makes it clear.
I feel this is less of a next installment but more of a "copy and paste" of the plot just to get something out there for the fans. Season 1 plot was decent at least but to copy and paste character development is just lazy. The onl good thing I can really say about this show's season 2 is that they give some characters a deeper background, but that's just about it.