This is only way only changes can be done in your body, because such situation force you to find new solutions, and consequently it means a jump to higher level of understanding aikido.
'New solutions' = possibly a different technique than the one you originally intended? I can see the benefit of learning to feel the attack and quickly find the most efficient and effective technique for a given attack...
Or the technique you meant to do, but done differently than you were originally doing it? I can also see the benefit of learning to feel the attack and figure out how to close holes and make a given technique work regardless of uke's attempts to counter or be difficult...