This is very similar to the nature vs nurture debate with children. You can't prove either way. You can belive anything you want to believe, it doesn't make it true. EVERY guitar I have made has sounded basically the same, including the pine guitar. People say It should have a lighter tone, it does not, it sounds like an electric guitar. Semi hollow guitars and hollow bodies sound different but that is construction not wood choice. Most hardwoods are relatively the same density baring some non conforming species. So the tones carried on those species are relatively the same.
Objects have natural harmonic frequencies, but that is usually only one frequency which does not prove any advantage to an intrument that produces different notes from the same body/neck.
I stick firmly in the camp that if you can't prove through scientific method that it exists then it does not exist or is too negligible to prove useful.