I will have to yield to your experience then. I mainly thought of it as a naive type of sensible argument, given people were not all that concerned about tracking and particularly browser fingerprinting. I guess back then, the main thing was web developers who used flash needed to check for it. But those people were anti-open web back then and deserved to be ignored by the browser makers.
I am guessing you were strongly in the open web camp back then. I am glad we sort of won that particular battle, even if we lost so many others.