If a photon of 475nm strikes my retina, my brain registers it as "blue," whereas a photon of 650nm is "red." If I ask the question "what is oscillating, and therefore causing the change in wavelength (and thus frequency) that I observe?" I'll receive an answer invoking alternating orthogonal electric and magnetic fields. Since a single photon is itself a quanta of the EM field, there is an easily understood relationship between the wavelength of light that I access directly when my eyes register the color "Blue," and the QED entity described by "the photon has a wavelength of 475nm."
My question is this:
Why is the wavelength of a photon discussed and treated as a physically real component of the world, while the de Broglie wavelengths of other (massive) particles are dismissed as "waves of probability."
The color blue registered by my retina is the product of very real wavelength in an EM field, which is itself composed of (built up of) field quanta of the same wavelength (within uncertainty distribution). Why do we alter the way we conceptualize de Broglie wavelengths when we speak about particles/atoms/molecules, when diffraction and other characteristics remain, and the maths remain the same as well?