Reading this thread for the first time, because my bitterness is new, and resolute, and endgame now, I was thinking about the difference in my reactions to Moira's death and Sara's death, because they were two of my favorite characters. I was really gutted at the end of Moira, but I think it was simply a matter of economics--I suffered the loss but I still had some other investments keeping me around. But with Moira gone and now Sara gone, and Thea AWOL and seemingly tied to Merlyn [who I don't care about], I guess I'm really dunzo. I like Stephen, but not enough to watch a show telling stories about characters I don't care about. Felicity has some funny lines and I don't dislike her, but I don't really relate to nebbishy characters like that. I kind of prefer straightforward ass-kickers.
So I think it turns out that a show can't actually eliminate all the characters you're interested in and still be interesting. What a revelation.