There's no way that whole "abandon all our technology" thing would have actually worked. First of all, I doubt most humans growing up in a high tech world could suddenly transition to a zero tech world and survive long enough to breed. Second, are we supposed to believe that the fleet, which couldn't agree on ANYTHING up until now, just unanimously decided to dump hygiene, medicine and all but the most primitive shelters? It makes no sense.

The driving themes that were the only consistent aspects of the show (i.e. is the human/cylon race worthy of surving) were completely abandonded in the finale.

Baltar's purpose/fate/destiny turned out to be nothing more than carrying Hera into a room.

The montage of modern day robots at the end of the finale.

The whole ending making NO FRAKKIN sense

A group of people who after years of being told that unity is their only survival would break up into small nomadic groups after they find a habitable alien world.

Kara was an angel.

Since it was established that humans and Cylons can interbreed, why is Hera so integral to the survival of both?

Cally was driven to contemplate suicide by the disgust she felt at being used as breeding stock to create her abomination cylon-human hybrid baby. Except she would have already known that it wasn't Galen's child and therefore wasn't cylon at all.

The way Cavil dies in the finale

The second earth found in the finale.

The Colonists completely reverse their goals at the end. They wanted a place to settle, to build their civilization, or maybe a new human/Cylon civilization, something with hybrid cultural vigor. This was the whole reason that the humans were continuing onward… and that’s exactly what they give up in the last few minutes. They decide to go live as hunter-gatherers, consigning their descendents to endless millennia of nasty-brutish-and-short.

And in this view of things, Starbuck really does bring them to “their end”–the end of the human civilization, and the end of the (humaniform) Cylon civilization as well. They throw everything away, and hope that their distant, distant descendants will do better.

The Colonists give up. They fail. After going through hell to preserve their culture, they pitch it out the airlock on a frakking whim. Break that Aesop, guys!

Too many main characters turned out to be Cylon sleeper agents.

God, or whatever is responsible for all of it.

All Along The Watch Tower was written/composed by Sam on Cylon Earth, but Kara's father taught her play the exact same song 2,000 years later on the piano.

The Human culture/religion was passed down for 150,000 years.

The Kobol starmap.

...and they did not have a plan ...at all!

A major theme throughout the series is that the Human and Cylon race must come together/combined to survive, but at the end they go their separate ways.

Their are planets (13, if you count Kobol) that have exactly the same species of animal/plant life found on this planet.

The whole coda.

Agriculture existed 150,000 years ago, and the whole damn time line of human history.

Lee, or somebody else teaching the indigenous species to talk/trade and interbreeding with them.

Lee's "rescue" of his father at New Caprica making no sense, with his complete lack of tactics - like leaving his Vipers behind - leading to the loss of the fleet's greatest military asset - the Pegasus - to ensure the survival of the crumbling and horrendously damaged Galactica.

Season 4.5's complete and utter lack of character-driven story-arcs, and disregard of any such arcs that had been started in 4.0 (ie, Tigh and Caprica/Liam).

Season 4.5 (especially the finale) featuring Tigh and Tyrol in glorified cameos.

Baltar's constant switching from hero to coward to hero to coward, and lack of focus in season 4 in general. In the season premiere he's willing to die to save a little boy he's never seen before, but in the finale, he won't stay on the Galactica and shoot some Cylons from afar. After having his honor challenged by Lee to his face, no less.

Billions of people had to die in order for the Human and Cylon race to come together.

Sam regains his memory of his past life after he was shot in the head.

Racetrack nuking the Colony, and saving Galactica from beyond the grave.

Lee allows his father to go off in isolation on new earth.

Athena and Helo living on new earth.

The incoherent, hand-wavey appeals to Higher Powers. Of course characters in stories refer to Higher Powers imbuing their actions with meaning. It’s because there is a Higher Power making sense of everything; it's called an author.

Head Baltar, in the very last scene, remarks that "You know he doesn’t like to be called [God]." Yeah, he likes to be called Ronald D. Moore.

It's a rookie bit of Bad Writing that was ably described more than two decades back in The Well-Tempered Plot Device. Stories are largely meaningful insofar as they reflect the real world. Relying on the artificial nature of the story as a major plot pillar is bad writing.

Gaius Baltar, is he a cylon? no he's not.