The later end when I figure out enough of the story to be satisfied, or when the tedium of the gameplay exceeds my desire to experience the story.
I reached a similar point in this game (Elite) shortly before the great Oddity release. After looking at the crap I'd have to do again to engage aliens, and the horribly buggy release of the FPS, I said 'no more' and decided to wait for upgrades to Horizons. I then found out that bug fixes and upgrades were done with respect to Horizons.
And that was the end of that.