No, it's not because I'm an 18-year-old female with no children. It's because Joyce was entirely clueless for the 2+ years Buffy was a Slayer prior to this argument. She didn't notice a thing even though all the evidence was laid before her. As Buffy said, there was even blood in her clothes that Joyce had to wash out. That's something you ask your daughter about, or at least mention in passing. You don't pretend it's not there. And, beyond that, how many times did Buffy sneak out of the house? Basically every night for 2+ years, and her mom didn't notice? And c'mon, it's not like Buffy was always being particularly stealthy about it either. Half the time she thundered out of her window. Sometimes it seemed like Joyce was actually GIVING HER PERMISSION to sneak out. I can't remember what episode it was, but Joyce said something like, "I'm going to go eat dinner. You can stay up here and sulk if you want, I won't bother you, but if you want to come down and eat that's okay too." In that moment it's as if she knows Buffy is going to leave anyway and is actually condoning it, whether or not that was her intention. Beyond that, how many stakes, crosses, bottles of holy water, etc etc were always laying casually around Buffy's room, hanging out of half-closed drawers and whatnot? Granted, a lot of it was well-hidden, but a lot of it was not. I don't know about anyone else, but that's something I'd ask my kid about too. After a divorce, and moving to a new town..isn't that the time you should pay particular attention to your kid? Yet Joyce remains utterly clueless. It really upsets me. It's the same thing as a parent not noticing their child is into heavy drugs, or depressed, or something like that. Then suddenly the cat's out of the bag and she's all consumed in the concern parent role, and I'm supposed to sympathize with her? Buffy is supposed to sympathize with her? I have no doubt she was genuinely concerned, but where was all this concern before?
She reacted a mother in that moment, yes. And her harshness is forgivable because of that. But the years of neglect and ignorance before this scene...I just don't know if I can say the same for that.