The more I think about it, the angrier I get about how little sense it made. It just seems like an easy way out of the whole 'the snake is coming' problem that the writers dug themselves into.
I know there are some good creative types on here that rationalise these problems, so I wanna hear it!
Well, I don't know if I qualify as good creative, but I'll give it a shot.
First of all though, you've gotta tell me what does Lethe's bramble have to do with this? That might be a bigger puzzle. I'm lost on that one.
OK, but to attempt a
fanwank on the questions you bring up concerning the students' willingness to help bring down the mayor, and Sunnydale's reaction to what happened.
You ask why it's never mentioned again. It is though, and more than once. I'm not into looking for the references right now, but they're there. There might even be at least one from Cordelia in Angel.
OK, so why would the kids help? Remember The Prom? Remember how they suggest the students actually knew Buffy was hero girl? OK, also do you remember this from The Harvest?
Cut to Sunnydale High the next Monday. Everything appears normal. Buffy
walks along and overhears Cordelia talking to a friend.
Cordelia: Well, I heard it was rival gangs. You know, fighting for
turf? But all I can tell you is they were an ugly way of looking. And
Buffy, like, knew them! Which is just too weird. I mean, I don't even
remember that much, but I'm telling you, it was a freak show!
Girl: Oh, I wish I'd been there!
Cordelia: You should have been there. It was so creepy...
She and her friend walk off. Buffy meets Xander.
Buffy: What exactly were you expecting?
Xander: I don't know, something. I mean, the dead rose. We should at
least have an assembly.
They run into Giles and Willow, and the four of them continue to walk.
Giles: People have a tendency to rationalize what they can and forget
what they can't.
Buffy: Believe me, I've seen it happen.
There's a transition in the Sunnydale student body from what Giles describes in The Harvest to the pink umbrella acknowledgment of Buffy as hero in The Prom. At that point Buffy can say "Jump", and everybody says "How high".
On the Sunnydale reaction there's that scene after School Hard where Principal Snyder and the police detective invent an excuse for what they appear to know was a vampire attack. They say they will tell the press it was a gang on PCP. Apparently that's the way that sort of stuff is done in Sunnydale. It's never really explained exactly why. It's suggested it was a policy of the Mayor's, but it appears to continue even after he's gone. I guess it just got comfortable as a way to deal.
Also...didn't Dark Willow, or somebody say something about the police in Sunnydale being profoundly stupid? And what's-her-name (was it Nancy?) who's boyfriend turns into a giant worm in Beneath You suggests there is talk about the kind of things that go on in Sunnydale.
Will any of that help? It's kind of like connect the dots, and create your own rationalization.