That's interesting, I never saw it like that. I mean, yes, obviously it was a Buffy-centric show, and we see how much Buffy's trying to juggle while Joyce doesn't. But it never occurred to me that the scenes we actually saw didn't happen that way.

I see Joyce's behavior as unreasonable and poorly-thought-through... but also believable. Some parents really aren't good at showing any care for their kids' emotional well-being, or cutting them any slack.

Likewise, Joyce being idealized after she died made total sense too -- people idealize those people (or communities) they've lost, it's part of expressing how huge the loss was. But the loss can be huge even if the person (or community) was imperfect.