And real nimby impact (as opposed to the impact imagined) scales much less than quadratic, because larger rotor implies lower rpm and rpm has a huge impact on perception. Small rotors emit a very strong "presence" when you are anywhere near, whereas the tallest ones feel as if they are on a different plane of existence even when you are standing right at the base. Certainly not quite as disconnected from reality as airliners passing by at cruising level, but it's a similar effect.