I think the point is that this sort of power may not be as necessary when you are young and vigorous, but as you age, it becomes more and more necessary if you plan on holding your own with the young guns. I hear Shioda Sensei really started implementing the idea of 'soft' kokyu ryoku sometime in his 40s...I'm 44 as of yesterday, and I need a different way to do things. The 20 something brown and black belts can be a hand full without it.
Best,
Ron