David Miller's logic seems rational enough. Let's look at Budweiser for a moment. Budweiser's fermentation vessels, are rigged with a level at the top that catches all the fermentation scum, that is up and kicked-out during primary fermentation. The brew master at So. Cal Budweiser say's, the purpose of the top level inside their fermentation vessels is to catch all the harsh, astringent material that would other wise affect the flavor of the finished beer. This may suggest, that skimming the foam in the kettle along with the coagulated hot-break would lessen the harsh flavor contributions.
Skimming the braun hefe during fermentation is a different topic, really. In this case it's the incredibly bitter hop resins that attach to the krausen that you are skimming.
I'm not sure this actually suggests that the boil break material also contributes negatively to flavor.