books are a victim of bad timing. Trek
audios sold great for a very long time, and then sales started to plummet to the point where it wasn't cost-effective to keep doing them, especially since sales of audiobooks in general were going down. But then the MP3 revolution hit, and suddenly sales of audiobooks went back through the roof after being in the toilet for so long. Sadly, by that time, S&S had given up on Trek
audio, and nobody's really tried to start it back up again.
I have no idea what the rights situation is with Trek
audio these days, honestly, so I have no idea what would be involved in starting it back up again......