Yep, they just switched again. I get the strong feeling that the first guy, in charge of S1-S2, had the right vision for the show and ever since then, it's been a succession of people trying to imitate S1-S2. Sometimes it's done well, like S4, but they've lost the original focus, which is that Dexter is not supposed to grow. He can't
- if he can "cure" himself, it not only renders his backstory a joke (could Harry have cured him in childhood by getting him good psychological help? He never tried as far as we know!) but it violates the integrity of the character (it's too easy of a solution) and robs him of what makes him interesting in the first place.
No, the point of this particular story is for all the other characters to change. Dexter's dilemma is to stay exactly as he is, and get others to accept him for what he is - the fantasy parade at the very end of S1 told us what the show's premise is. Realistically, people like Angel and LaGuerta aren't going to change their minds about serial killers, but Deb and the kids might.