it's just fan fiction.
No, fanfic would have been one written for personal pleasure and not paid for and released by copyright-holding licensors... There's a difference between fanfic and professional.
And indeed between fanfic and fanwank, which is surely the more accurate word!
But at the end of the day if you didn't like it you didn't like it - nobody likes everything and nothing is liked by everybody. You've liked other stuff I've written (surprised you mentioned Mission Impractical though - that's no classic, and a bit... would-be "wacky" even for me), and probably people who loved this would other stuff I've done. So, no worries, there'll be another Trek book along in a couple of weeks.
Out of the four pitches I'd love to see make it to another Trek book, I suspect one you'd hate, one you'd love, and two could go either way...
Here's hoping to find out which it is someday...
ETA- oh, command track, remember Geordi was Riker's first officer in Redemption Part II as well, so he's presumably taken all the exams and stuff. Doesn't matter, though.