You are right with your arguments, but I was unclear as to what I was trying to say. I think that the lower barrel proof allows more of the fruit flavors to develop and mature in the aging process. I believe that they are one of the more water soluable flavors developed in the aging process and as a result when it comes out of the barrel at 125 to 140 proof, there is more water added to water down the fruit flavors. That is not to mention that when you consider that less water in the barrel means that there is less of the flavor developing to begin with so the extra water is a double whammy to the flavor.
There is a lot of discussion of barrel aging and the contribution the bareel makes. Most of the discussion has to do with the tannins a vanilla caramel extracted from the wood by the alcohol. But the wood is also gowing to effect the other flavors from the white dog as well. Many of these grain flavors are remaining in the white dog as part of the water content, not the alcohol content of the white dog. Brown-Forman spent hundreds of thousands of dollars a few years back to have the best organic chemistry lab in the world, that is part of a German Univeristy, do a study of aging whiskey in the barrel. They determined that many of the barrel flavors that are considered desirable, are more water soluable than alcohol soluable. In other words the lower the barrel proof, the more desirable the flavor. I think these fruit flavors are one part of the desirable flavors found with lower barrel proof and that is why you hardly find them in modern bourbons.
"Our people live almost exclusively on whiskey" - E H Taylor, Jr. 25 April 1873