First of all, how do we know this interview was entirely on the level? Personally, I don't take David as the person to openly criticize his former co-star like that. More could've been said, and some stuff could've been tampered. You never know.
And if this interview truly is legit, then I think it was entirely out of line for him to say something like that. Sarah's schedule is extremely busy as of now. And I know it wouldn't hurt to just take off a week to do Angel, but I'm sure she wants to take things one step at a time.
She's did the same old thing for seven years ... she just wants to do something a little different for awhile. Cut her some slack. 🙄