@Lustig Andrei,
Yes.
And in
Dexter's case, we empathize so easily because he is the
narrator ... whatever occurs, we hear
his version of events,
his voice. So our whole perception is coloured by his perspective. And we aren't privy to anyone else's perspective of the same events to anywhere near the same extent.
I'm trying to think of other films/tv productions where the
voice over device is used in this way. I know there are many, but examples escape me right now.
You know the main character/narrator so much better than everyone else in the story, how could you
not empathize with them? (Unless they are a deliberately created as unsympathetic or evil characters.)