This isn't necessarily true. I'm one of those curlies who Massey claims cannot possibly exist: my hair is not the least bit dry, and in fact actually tends toward being oily, despite the fact that I use shampoo (though now it's a sulfate-free one) and diffuse every, single day. I know I'm in the curly minority, but I'm not the only one in the world like this!
Hair type: Completely confused: mostly 3a, some 3b parts, and even 2 in places; very fine and thin.
Products: Elucence clarifying & MBC; CK, F/X Curl Booster Fixative Gel (when I can find it)