There are several things that factor in a Hypothesis release date:

* People that are currently playing (They don't wanna lose them if they wait too long and players think it dropped of the planet :P)

*Beta/Alpha bugs that can cause the game to be pushed back.

*Things that they may want to add for the release that can cause the release to be pushed back


The first one is very critical , they don;t want them to drop off the face of the planet with this game. They need all the subscribers they can get.