We quickly binged seasons 1 and 2 and it was great. We quickly moved into season 3 as three episodes had already aired by time we finished binging season 2.
I can imagine watching every season of Zoo with 9 months in-between has prevented many people from comparing season 1 with season 3, but wow is season 3 bad! It's like watching a slow descent into insanity. Season 1 seemed fresh and interesting and even season 2 seemed like a logical follow-on to the story of season 1. Season 3, however is like a poorly built add-on to a house. You can just tell it doesn't fit. All the things I liked about the characters in seasons 1 and 2 were completely destroyed in season 3. Every episode seemed like they were literally choosing the worst possible decisions. And the finale wasn't even a finale!
Call me old fashioned, but I like the seasons of a show to have an arc. The season finale closes the first arc and starts a new one for the next season. First of all, I desired for this whole show's arc to be closed. But even if not that, I would have at least desired a NEW arc for season 4 (if there is one). But no, instead they just bunted the ball. There was no clarity, no cliff-hanger, just all the characters literally yelling at each other and then the credits screen.
I hope, hope, HOPE that CBS just cancels this show. It doesn't deserve a season 4, I don't see any way for this show to redeem itself. I'm a completionist at heart, so I don't like to leave to shows, movies, or books unfinished. But if Zoo comes back with a season 4, I'm going to have to think long and hard about how committed I am to my completionist tendencies because I really don't want to see another episode of Zoo...which breaks my heart because I loved season 1.