This is precisely why using neutrinos would be an attractive idea - the signal could travel over extremely long distances with very little diffusion/attenuation

This is precisely why using neutrinos would be an attractive idea - the signal could travel over extremely long distances with very little diffusion/attenuation. (I.e., as long as you have a narrowly focused beam, to control dispersal, the beam itself won't be weakened by any intervening debris.)