I frequently hear in reviewer comments about "laziness on behalf of the author" and how the story could have been much better if the author had done more work. Recently, I finished reading the entire Mr. Tucket series by Gary Paulson. I couldn't help but notice the original was about 170 pages long and the four sequels were all about half that long.
In my opinion, the series could have been a lot better if the four sequels were as long as the original. Maybe if they had each been about two hundred pages long it would have been better.
The first entry in the series had been published in the 1960s, and the first of the sequels were published three decades later. I'm sure a lot of people who read the original and waited many years for a sequel were disappointed. Throughout the rest of the series, important characters are introduced or reintroduced, only to be either written out or killed off quickly. It's as if Mr. Paulson was in a hurry to finish the story and complete the series after so many years after writing the original.
This is a fine example of author laziness. What other examples are there that anyone else has seen?