The whole series relied on David not knowing what's going on. Letting the character relax / normalise at the end would probably block off a lot more plot choices. I feel sorry for David but it's the best choice for Series 2. To be honest, too many US based shows end up with the 'everything is now great…except this one…

Probably because as you get older, once you've seen the same old fight scene, car chase, massive explosion, etc., over and over again, you want some actual meat with all that sauce. One Netflix Marvel show is worth 10 Arrows or Flashes and don't get me started on LoT..