I am not selling mine (hell, even consider a second) but it could be mainly due to poor manufacturer support or not getting what they expected, especially those who needed a "baby cradle" ride... So they are selling and getting RAV 4 or some other like honda.
As for the gas prices, no matter what SUV you get, you will face similar MPG, so if that's the reason they are selling, what a pity. (unless they go sedan..
)
lastly, why so many KJs? Because it was the best selling vehicle in its class, there were over 220,000 sales in 2005 and probably half or similar of that in 06.
So you are bound to see many sales of used KJs.