Marion - I think part of it might be that people's perceptions are limited by their exposure. When I once asked a coworker and received the "all kinds" reply I then asked her to be more specific. That was answered with "Pop, Retro 80s, Classic Rock, and a little Country. But I don't like Classical." But to her that was "all kinds" because that was everything she'd ever been exposed to - what was played on a couple different radio stations. If you're not a person who is musically driven you may not be exposed to much, or what you are exposed to may not be remembered.

Another problem with answering is how do you decide at what level to categorize music? If someone says they like blues, does that include both Robert Johnson and Robin Trower? Jazz can be just as varified. If you say you do (not) like jazz does that include all of Early Jazz, Big Band Jazz, Swing, Bebop, Cool Jazz, Hard Bop, Post Bop, Free Jazz, Avant Garde, Fusion, and Post Modern Jazz? Is Louis Jordan considered jazz or blues? How many laymen can differentiate between Bach and Beethoven? A person might like one but not the other, but unless (s)he had the drive to research them I would suppose that chances of knowing the difference are slim to none.

And some people are just lazy and saying "all kinds" is easier than thinking about it.