They lost me in the 10th episode when Dexter kills Logan; all he had to do was wait for Angela to come back after discovering Kurt's trophies and realize that Dexter was a necessary evil and let him and his son go, then there would have been another season of Dexter: New Blood.
This ending was so lazy; I could tell that they decided to cut the entire series at that point, because Dexter killing Logan was completely out of character. Saying that 'Logan wasn't complying with what I wanted to happen' made NO sense, because all he did was give him the bottle of water, which he asked for...so how was he 'not complying'??
If anything, Logan and Angela would have had empathy and compassion for Dexter, because until THAT point, he'd never killed any innocent people and not even Batista could prove Dexter killed anyone innocent.
Dexter was also NOT the fault of everything, because the Trinity killer was already killing people before Dexter got involved, and he only killed Trinity out of revenge for killing his wife anyway. Everything made sense until this stupid lazy ending.
Now all they have to salvage any of the Dexter saga is offshoots and spinoffs, which nobody will want to see without Dexter anyway.
Congrats, you killed the only reason to keep watching.