Somebody in the comments to some entry (See how good I am at keeping track of this stuff?) linked to an interesting site about
Buffy "Loyalists" and "Jumpers".
To give a simple explanation, they propose that Buffy fandom is split among two general types of fans: The "Loyalists", who enjoy the entire series, and the "Jumpers", who feel the show had a significant decline in quality after S3.
Um...this ain't entirely unheard of, really. I know that here in this corner of LJ Buffy fandom, the later seasons get much love and discussion. Outside, though, you get more variety in opinions, and it's not uncommon to see the show being discussed only in terms of the first three seasons.
I'm not sure how frequent this is. To be honest, a lot probably comes down to perception. I enjoy the first three seasons, but the high school years aren't why I'm a Buffy fan. I find I have very little to say about them. So I do notice more when people ignore the later years to focus on the early seasons just because it doesn't mesh with my own point of view.
I find I'm curious about the linked site, as they say they got their data from searching for episode rankings, but they don't provide actual sources. Also, it's uncertain how many lists they took into account. So I'm not too sure on the data simply because I don't know exactly what it's analyzing. It is interesting to read through, though.
The site attributes some fans' unhappiness with the later seasons to "graduation from high school, the introduction of Tara and her relationship with Willow, the introduction of Riley and his relationship with Buffy, and the Initiative arc."
While I think that's all sound, I'd also add a couple more.
1. Spike becoming a main cast member and becoming "leashed". Some people like their evil...evil, and are unhappy with how Spike's character developed. See TV Trope's
Badass Decay, originally named "Spikeification". (I swear, someday I am gonna write that post about how the writers managed to integrate Spike, an antagonist, into the show as a regular)
2. The break from established formula.
Structurally, S4 is actually similar to S3. Lots of good standalone episodes with a fairly weak main plot arc holding it together (S3 seems to get more love because Faith is a more appealing character than Riley). And S4 still uses the "monster of the week" formula to play with the adolescence metaphor.
However, that formula stops being used as frequently and as noticeably, especially in S5-S7. And some people like the formula. They see it as a sign that the show is "running out of ideas" to break from formula.
Others enjoy the change and appreciate the broadening of narrative and thematic structure.
Different strokes.
Anyway, I find all this very interesting. *iz nerd* :)