Because my group got TPK'd once, and nearly so another two times![]()
It's a module in which it is very easy for the players to get in over their heads. For example, the TPK happened when they met Windharrow, who led them down two levels into a much higher level dungeon and straight to a boss fight that they couldn't handle. (I expected them to try to get off the ride before the end, but they didn't...) Another time they entered the Fire Temple about four levels too early, and had to beat a hasty retreat. The Stone Monastery nearly did them in as well, due to aggroing nearly the entire place in one go.
But the final few levels - the Fane, the final dungeons - really don't have tough enough monsters to justify their increased level. It wasn't necessarily a problem - it mimicked a lot of computer RPGs, where it gets easier the more power you acquire - but still very noticeable.
Interesting - this has been my experience too - and evaluating the lower levels (the nodes and fane), they do seem to have way less in the way of monsters and more in the way of hazards.
I could only assume that this was to make it easier for the characters to clear out the dungeons without having to rest every five minutes and ruin the pacing towards the end.
How did their fight against the Elemental Prince go?