How are you comparing aggressive? What makes the Wildpeak more aggressive?
The amount of space between tread blocks. Larger voids = more aggressive = more weight on each tread block = more likely to experience tread block movement which will affect steering, etc.
I'm not sure what size(s) you ran, but we can kind of make some assumptions based on tire weight.
LT285/70R17 LR E Wildpeak has a listed weight of 58.9LB. A KO2 in the same size and load rating is 58.2LB. The KO2 is a little lighter, but you would think if it had a much thicker/stiffer sidewall that would result in a noticeably heavier tire. Yeah?
Something else is your alignment. Have you had it checked recently? How many miles were on your summer tires when you took them off and put the Wildpeaks on? The reason I mention this is if you have some miles on the KO2s then they will generally wear to conform to the alignment, if your alignment is off and you put new tires on then the results can be what you experience. This is another annoyance I have with my current Duratrac tires, they are wearing poorly even with a perfect alignment. Might be PSI related, I've bumped up the PSI a little to see if it helps. Getting to my point, I had my shop do a rotation and check my alignment because the tires were developing poor wear patterns (In the 88k miles on my truck this is the first time I've had poor wear and had to rotate my tires). Alignment was good but when I left the shop my truck was pulling hard to the left and the steering wheel was off-center to the right when going straight. Took it back, shop swapped the front tires left to right (They were previously on the rear for about 8k miles) and the truck drove straight and true, no more pulling. Super strange because there's really no alignment to be done on my rear axle and it was well in spec so there was no reason for the rears to wear unevenly but they did.
Maybe you ended up with some non-uniform tires. I'm not questioning your bad experience or suggesting it didn't happen, I'm just trying to think about what the issue could've been considering the high number of positive reviews of the Wildpeaks.
Maybe I just got some crappy Duratracs, too. Who knows.
Whatever the case, I'm not trying to change your opinion of the tires. You had a bad experience with them and good experience with others. Just thinking out loud.