Actually when the development started, and have they really thought they would be able to do this complex game in Dec 2014, when they didn't worked on similar project before and didn't have both libraries they made themselves and crew experience with games like that?
The $900K version would not have been so complex. =) Before the Kickstarter campaign even ended, we announced that the release date
would be later. It was important to me that backers who were bothered by that would have a chance to back out before funding closed.) As you might expect, Wasteland 2's retail launch in September 2014 impacted TTON's schedule, as I described
in June 2014, when I announced that TTON would be delayed until the end of 2015. There were some other delays and the game has been in full production for a much shorter period of time than casual observers (i.e., those who haven't followed all of the updates) might think.
(That said, I take responsibility for not meeting the late 2015 date that I had advertised one-and-half years ago. But I think TTON's players and backers will be significantly happier than they would have been in the alternative universe in which it did ship before the end of this year.)