Concerning Frank Baum, I recently finished reading the first 6 Oz books to my daughters.  He really kept trying to end the story.  The only later book I've read so far is Scarecrow of Oz, which I found to be very different from the first 6.  Of course, the second book is a different formula than the first, but he was innundated with requests for more Dorothy...

Artistically, there's the example of someone like Keith Giffen, who has gone through many artistic styles, some more liked than others.

Could it be because an artist finds it to be more work than fun, where it should be both.  I believe JB has talked about "challenging himself" when it comes to his art.  In this way he's trying new things to present the story.  It can be the duo-tone, or panel layout, or any number of different things.

Something else to consider is the changing of the comic book script.  In the "old days" there was a lot more actual story in one book than you can find now.  A lot of information had to be conveyed in a little amount of space.  Today the first few pages of Fantastic Four #1 would take at least 3 issues, all filled with HUGE panels of talking heads.

The same story can be told for rock bands, too.  "We don't know what we are doing, so F it, let play more aggresively and turn that bitch up to 11."  Later, when the master their instruments, they don't play with the emotion (attitude) they did when they were starting out.  They want people to hear the music and therefore people don't feel the music as much because it isn't as raw.

I think Kirby is an exception.  I think his work became more raw and more creative as he progressed.  His golden age stuff is okay, certainly better than some of the other artists at the time, and his early silver age stuff is very fun, but when he perfected his style, WHAM, there was energy unlike any other creator.

Edited to add: I prefer work done later in a creators career.  Then you can really see some fine art.  I do like the earlier work of rock bands, tho.

When you were a kid, did you correct other kids' slang or criticize their lack of thought or insight?

Yeah, but I was kind of a prick when I was a kid.

The same story can be told for rock bands, too.

Had that thought, as well. There's the idea that rock artist(s) have their whole life (to that point) to write their first album...and only a few years (or months) to put together subsequent ones...