As I understand it, for a miracle to be credited to a saint (that is, a miracle by God in response to a saint's intercession) the petitioners must testify that they asked for that saint only to intercede, no others. Which apparently means telling your family and friends who might be praying for you - "John Paul only, don't ask the Blessed Mother, don't ask any one else." And I think it means not even asking God directly, but only through the saint's intercession.
I don't think I could limit myself that much; I'd be calling on all the big guns and everyone I loved who I believed was in heaven, and of course directly God, and I'd be asking people on earth to be praying to God, and since a lot of them would be Protestants...
Mrs Vs
And since the big guns might be busy listening to somebody else's prayer, you would want to cover as many bases as possible. I'm sure the ex-pope is very busy these days hearing all those prayers being directed his way. I mean, does he have to take them one at a time? Does he put you on call waiting while he deals with the current crisis? Image if just 1% of all the world's Roman Catholics (not to mention some errant protestants or Orthodox) starting praying to the pope at the same time. And how do you know he's not handing the calls off to some long forgotten popes from, say, the 11th or 12th century with extra bandwidth?
It certainly seems preferable to go right to Christ since we know as God He has the bandwidth to deal with all those requests.