Isn't the point that it's less magical - stuff goes where you expect it and does what you expect, not where the framework magically and by convention places it?
I believe bikeshaving's point above is that you learn the semantics of generator functions in JavaScript and that's your 'magic convention' - one that's not unique to this library because it comes form the languagee
If the OP was saying that Crank is less magical then I agree. Although it always made me sad that we measure APIs based on how little magic they bring. Like go to Disney World or something.