Heh, I read reviews and summaries, and it seems that people are mad because Dexter pretty much won. Everything went perfectly for him. Breaking Bad ended exactly the same - sure the main character is dead, but everything went about according to his plans. Skyler is safe, his family will have money, the brotherhood is dead, Lydia is dead... No more blue meth... Everything was perfect.
The Dexter finale was just a clusterfuck of some good ideas with god awful execution. Dexter didn't "win" at all, it was just terrible.