That is easy - they are supposed to be maintaing some façade of the same person and avoiding the radical break. This is logical and logical internally to the idea of the series.
It was not dumb filler - it is logical to not make the radical break and the “errors in casting” for the targets for sending back based on the originally limited information the future has on the past seem logical (although one plot twist for the doctor I think was not fully consistent, but I suppose it could be assuming the incomplete knowledge even for the characters, which is sensible).
I have discovered this series myself although very unusually I like the French version over the english original.
I just discovered and now finished all three seasons, one per week. It really hooked me, much as the early episodes of the new Battlestar Galatica did. I got emotionally involved with the characters, especially Marcy and David, though not so much as with Jeff and Carly (and the always crying baby). Marcy in particular, with her back stories, really moved me. The final bus scene reminded me of the end of The Graduate - what are they going to do next?
The final episodes where the world kept getting worse and worse, in spite of the traveler program, were frustrating to me; atomic explosions are never good! I liked the references to quantum computing and AI and nano-technology. Of those, only AI is actually going mainstream (for now), which gives you something to think about. I wish we could have seen some glimpses of the future, in particular seeing what the director looks like.
I liked the final “reboot” sequence, which called back to the skydiver reboots. It gives the whole series a good stopping point, while allowing for a future season, possibly not in the near future with different actors. If there’s never another season, I’d be fine with that.
I have to say, I am not too disappointed. The show went downhill after the first season IMO when they moved away from trying to change the future to dealing with the civil war.
Nope. I just watched season 3, and was trying to find out why Marcy was normal at the end–I had forgotten that she was originally normal and then damaged by 001 (this thread cleared that up.) I had also forgotten the origin story of 001 (which Wikipedia cleared up.) The reason that Grant was standing staring out the window after sending the e-mail was because he was in one of the World Trade Center buildings and was waiting for the airplane to hit, as 001 was supposed to do. So no mo Grant.
I was impressed that Trevor’s brain disease wasn’t quietly forgotten about. That sure did seem like the kind of thing that is introduced as a huge deal, resolved by the end of the same episode and never brought up again. But it continued to be an issue until the end.