After watching a recording of the episode, I have to agree that the ending could have been thought out better. But I still think it's an acceptable one.
Glad to see the series receive an ending. Genndy deserved an opportunity to finish his story, and he did so appropriately.
The theme was obvious early on, but this should have been spelled out by the characters early in the series. They took too long establishing the world of this series to fit the 12 episode frame, and the pacing was off for that reason.