Lets get some super simple maths out of the way first:

For every time we get KK v's someones AA, we'll get AA v's someones KK. Thats a 0EV situation and we shouldnt worry about it, its pretty much irrelevant as long as we're using proper BRM.

Next, refusing to get ai with KK unless we have the nuts would be an enormous mistake as a general rule to follow. Sure we should fold sometimes, but for a reason other than "we dont have the nuts".