Which imho didn't work, because they'd spent too much of the season showing a depressed Buffy using, taking advantage and manipulating someone who loved her and didn't have the moral understanding to realize that what Buffy was doing was hurting her as well as himself.

I agree; that's why I came away from that bathroom scene thinking "Well, hell, he's only got an extremely crippled moral compass to guide him, and the sexual behavior she's demonstrated to him all season has led him to honestly believe that when she says 'no' she really means either 'yes' or 'seduce me into it'...why SHOULD he think that this time is any different?"