I don't think that she's failing to take responsibility for her feelings in Lovers Walk -- she's admitting that, yes, she loves Angel in a way more than 'friends' way. Because of that, she's decided that they shouldn't play at being friends. Angel wants to know if there is any way that they can still see each other. And Buffy's saying no. Because she knows that Angel loves her and that he's not going to lie to her about it.

In As You Were, I don't think that she's doing that either. She wants to believe that someone loves her, even if it isn't who she wants, even if it isn't someone she loves back. She knows that Spike does love her. I think that AYW may be the episode where she finally does figure that part out. That he really does love her, in his own fucked up way.