for the record, const const * is redundant. I think const is only so confusing because you can write it two different ways (char const * vs. const char *); if only the former was allowed, it would seem a lot more logical.
Exactly: if 'int const * ' were common, it would be relatively clear that const goes after the type of the thing that is const - but the overwhelming use of the alternate form, 'const int *', makes it more confusing what to do.
So it all makes sense in terms of the grammar. Admittedly, it can be difficult to remember, but pointers and const correctness are complicated and combining them is going to be complicated to write out no matter what grammar you use. Even if the grammar was restricted, it's difficult to remember this type of thing and if you encountered such code in the wild and had any doubts about its semantics then you would look it up on Google before modifying it (right?)