Well, for jurisdictions where dedication to the public domain is not possible, CC0 includes a fallback license. I suppose I could have used the words "public domain", and that would have made the intention clearer — so thank you for raising that point. However, if you are going to do a public domain dedication, you really should use CC0!

PS: Why assume everyone is "ill-informed"? We're all learning together forever: you, me, amyjess, other readers...