Because that's how the compiler parses it. The * binds to the variable not the type. Think about char* a, b; This suggests that b is also a char *, but actually it is only a char. Much clearer when you write char *a, b; (Not that I would advocate doing either - even better to have two separate declarations - but it illustrates the point).
Ian Brockbank "Legacy systems are systems that are not protected with a suite of tests. ... You are building legacy code every time you build software without associated tests." - Mary and Tom Poppendieck, Implementing Lean Software Development.