Of course, you can experience exactly the opposite behavior at a computer or electronics store. The younger salespeople are much more likely to provide detailed information and to have a familiarity with the product line, in my experience.
I see no reason to assume that this discrepancy has to do with anything other than experience on the part of the salespeople. I'd expect more informative answers from an older staff member at a hardware store because it's likely that staff member has worked more extensively with the tools than a younger staff member.
Why do you attribute this to a "dumbing down"?
-- Matthew Snyder Philadelphia, PA