NBC quoted low ratings and played the 'writers strike' card to cancel Journeyman.
After the series got cut off at the 13 episode mark, viewers were left in the dark as to where the story was headed. This was particularly annoying since a few different strands of story were developing during the shortened season.
The creator of Journeyman - Kevin Falls, in an interview over on AICN had the opportunity to let some of his plans for Dan Vasser out of the bag. Though this sounds like a good thing, the down side to this is that the interview wasn't going to hit the 'net until they knew for sure that we wouldn't be seeing any more of Dan Vasser...
Here's where the show would have gone had it stayed on the air...
Katie and Dan were going to split up for a while. Jack (Dan's brother) and Dan were going to live together and then Dan and Katie would get back together.
Livia (Dan's time traveling ex-fiancée from 1948) was going to die in episode 20. Dan was going to save her in 21. And in episode 22, Dan would come back to his house in the present and find someone else would be living there. Katie (his wife) and Zack (his son) would be gone and this time Dan would have no idea how to get his family back.
Through it all, there was something bigger than the government that was tossing Dan and the other travelers around time. The underlying reasons for the time travel leaned towards a good purpose.
Livia's original travel purpose was to get Katie and Dan together, but then the writers felt that Livia was keeping some secret from Dan that was huge and tragic.
Livia only went forward in time and Dan backward because they each had a specific and separate purpose. One of the side affects was the tragi-romantic notion of Dan and Livia never being able to live in the same time.
Sooner or later in 2008, Dan would have encountered an elderly Livia.
That would have been a great tale to watch unfold.
Kevin Falls went on to lament that he wasn't so much bitter towards NBC as he was towards the mainstream critics who dismissed the show without a second nod (Screen Rant not included, since we loved the series). He felt they were doing some of the best television out there at the time and he was right.