That's not really surprising considering how much time Backers spend alpha and beta testing and tuning and improving that one area (we only had access to Cyseal after all) and Larian only took public feedback for Cyseal.. which explains why the game gets substantially less polished by the end. (The end temple would probably be the first thing we'd have slammed very hard had we known about it during alpha/beta)
Cyseal is also a nice example of what happens when a feature gets canned mid-development (schedules and time of day) that big village with many rooms and nooks with so much detail was only made that way to accommodate schedules, and when schedules were canned very late in development that area was as large and detailed as it was...
The other areas likely were never made for schedules, and it shows in how relatively barren and empty the 2nd area is. Though at least the area was pretty to look at...
