Okay, here is how I see it:
If we agree that Aikido is a standing fighting system designed ideally to defeat multiple standing attackers.
If we agree that BJJ (Judo by another name) is a ground fighting system designed to defeat a single attacker on the ground,
then ~ and perhaps it has already been answered ~ I didn't read the entire thread ~
If I was fighting against a BJJ guy, I'd like to
a) refuse to go to the ground, and avoid the clinch or take down.
b) when the fight does go to the ground, and a skilled BJJ practitioner can get you there easier than you'd care to admit, it's always nice to have a friend standing by, who could come up and kick the BJJ guy in the back of the head and knock him out ~ as the BJJ practitioner is not really trained for multiple attacker scenarios.
c) Even when on the ground, all of the wrist locks still work ~ Nikkio works just as well standing as it does lying on your back ~ you just need a wrist.....
d) answer his BJJ with my own BJJ.
I believe that these two systems are complimentary. In fact, I think of BJJ as Aikido on the ground. They are both effective, and both have their place.