It's possible that this perception of undifferentiated gossiping masses may be affected by bias in what the named characters listen to. The male population of Hogwarts might well seem like an undifferentiated Quidditch-loving mass if it weren't for Harry's tendency to fling Quieting Charms around when he wants to get out of conversation. (And, as a more literary reason, the girls' gossip is often plot-relevant whereas Quidditch jabberings wouldn't be.)
Cross-posted from the TVTropes forum. (There's more to the post there, but I didn't think it all needed to be repeated.)
Why would this important? Well, obviously, this memory represents a huge turning point for Harry. This is when he started to turn against Dumbledore. It suggested to him an interpretation of his parents' death in which Dumbledore deliberately set them up for it. This interpretation of events is itself a bit suspect; Harry thinks (Ch. 46) he came to it sometime during or immediately after the period of his Dementation, but he can't quite place exactly when that was, and it certainly doesn't appear in his narration at the time. He is presently sticking to this interpretation even after receiving information that should falsify it: according to Snape, it is impossible to tamper with the memory of a prophecy.
And, let's not forget, there's another reason this is important: the memory is leaking back into Snape. According to Minerva, Snape is held to Dumbledore's service by his guilt over Lily's death. Whether or not Lily was tortured seems to matter to him... perhaps Dumbledore had told him that she was. Now, Snape knows that the memory falsifies torture; this may weaken the bonds tying him to Dumbledore. This is without even touching upon Harry's interpretation of events, in which Dumbledore deliberately set up Lily and James to be killed in order to bring down Voldemort. Obviously, should Snape come to the same conclusion, his anger over the death of Lily will suddenly pivot and he will become unpredictable.
So, according to Moldbug, political changes over time aren't due to different movements waxing and waning in power and support, but rather due to one grand movement changing its mind? He seems to be a shockingly vanilla conspiracy theorist, given what I've heard of him. I'm surprised that LWers put up with him...