Some people got all pissy about certain elements, because it didn't follow what they wanted out of the show.
If your focus is all about the sci-fi, and you get annoyed with a few "wait... huh?" moments due to odd directional shifts in the plot arcs.
But I absolutely enjoyed every moment of that series. 🙂
The very last episode wasn't the most satisfying ending to the overall story, but it felt as if it really could have been worse (or more annoying: by not even daring to provide an all-encompassing end). Even so, my opinion is this: if 99% of the ride is enjoyable and satisfying, but the very last moment of the trip resulting in a funny taste in your mouth - would you say "I wish I never partook in that adventure" ?
There have been many stories (TV, Cinema, Novels) that were amazing every step of the way... until the final moments. Not entirely satisfying ending, sure, but an enjoyable ride nonetheless.