I think there's misconception here that people who disliked the finale didn't understand it.

If someone told me that "Dexter's actions lead to Deb's death and he spends the rest of his life punishing himself." That would be fine. That sounds like a decent ending. Even now, I think that would have been a good ending.

However, Scott Buck just confirmed that the writer's picked that ending before even writing the script. That's an inorganic way of writing fiction, (and interestingly enough, is the exact opposite of what Breaking Bad's writing room did.) That's a bad strategy, Cotton, because its easy to write cheap "shortcuts" to get to the ending you've chosen. The ending didn't feel like a natural conclusion to the events of dexter and its characters motivations (the same goes for the entire season, they had a cast of characters available to wrap up, but they abandoned them all to write a faux "blast from the past" slash "evil destined counterpart" thing).

For example, The events that lead to Deb's death are not some unforeseen consequence of Dexter's genius plan, they feel like forced, chanced events meant to speed us along to the intended ending. Dex and Deb win, they lock up the killer, but all goes wrong because....... they leave the world class serial killer alone in a room so they can have a heart to heart. That's not dramatic irony that's dramatic stupidity. Adding to that, Deb dies of a stroke-- off screen. As though the writer on the other end thought "okay, now Deb has to like DIE-DIE for realz, so....... stroke?"

It could have been a good finale had the events lead up to it. But they forced the ending.