Why Dexter, why and what about the elephant in the room?

First off, I'd like to note that I read a lot. I've noticed that often books don't transfer well when it comes to television and movies. Comic books, maybe, but novels not so much.  I've read a few Dexter books and I wasn't all that bothered that they strayed from the books.  The series worked--for four years that is.  After that it just kept sliding down that slippery slope that book adaptations often encounter.  Not to say that the actors weren't good.  They were the one reason that this show managed to stay on the air for eight seasons.  

And then came the finale.  

I remember watching the finale of the Sopranos and wondering if my television had bit the dust.  And then I thought, well, that worked, they couldn’t figure out how to write a good ending so they went blank, and so did the screen. The writers of the Dexter series should have taken note. 

Let me say this entire 8^th season was all over the place and with so many implausible plot points where could they be going?

And why isn’t anyone talking about the elephant in the room?  Ok we tolerated Dexter because although he was a sort of anti-hero, he did rid the world of evildoers who would otherwise fall through the cracks.  He had a code.  Hanna, on the other hand, just killed.  

From what I can recall, she murdered two innocent people with her criminal boyfriend, two husbands, one mentor, a hapless author, and almost killed Debra.  No conscience, just a whole lot of poison. And maybe it’s the mother in me, but I just can’t fathom giving my innocent pre-school son to a cold-blooded murderess.  I actually thought that she would be the one to kill Dexter.  Too easy I guess.  And so they both survive—to kill another day. 

Too bad the ending killed what was left of the show.