I could go into detail but in short I'm just disappointed at how senseless the show's become. At the end of s3 I was both hopeful and afraid of what the show will become; whether it'll only get better or become a typical 'AI vs humans' plot and that's what happened, even that came to an anticlimactic season finale that didn't really make sense. It's hard to imagine the same people who made season one made this. It had a slow start, then two good episodes and it fell off; the only episode that impressed me this season was ep4: generation loss; it gave me hope that the season was finally finding traction then it went downhill from there. The writers have ended some of the characters that had brilliant story arcs, with unsatisfactory and banal conclusions. So many of them were acting out of character and the reasoning didn't make sense. Several things were introduced in the season that lead to nowhere and it felt rushed. A lot of the fight scenes in the finale were also unnecessary. On a side note regarding the show as a whole, I wanted to see more of Clementine, she's the standout background character and was underwritten and appreciated.
I loved this show so much and I'm now not even excited to see where it's heading next if there is another season. Worst part is we had to wait so long for this season. This season was a drag, it might not be the worst season of any show you'll ever see but just how far the show has fallen from it's glory days accentuates how unimpressive S4 was as a whole.