Not all visitors go there for cures. Most of them were tourists.
Every year, there are an average of only 35 claims of miraculous
cures. Can the 67 recognised miracles be co-incidences that
happened only in Lourdes?
Doctors,irrespective of their religous affiliation(or none),are
invited to become members of Lourdes Medical Bureau.
The Bureau investigates all claims of miraculous cures with
tests available to medical science to try to debunk these
claims before a cure is recognised as a miracle.
As for regrowth of limbs, can't expect the maker to fix
everything that are broken by man himself.
Some animals do have to ability to regrow limbs. Scientists are
working on it.
35 out of 80,000? Granted there may be tourists, but the large
majority seek for cures. Starfishes can regenerate, so can the
tails of lizards, perhaps if humans evolve in the future, it is
less likely to be seen as a true miracle. However for now, if you
regrow a limb before my eyes, I would definately believe in your
god. Overall statistically speaking, healings in Lourdes remain no
more than sheer chance, taking into account the large numbers. You
are more likely to catch someone else's disease rather than getting
healed there