Why is the Mass Reflectance a DC-Blocker?

Physical intuition:

• The mass reflectance is zero at dc because Sufficiently slow force waves can freely move a mass of any finite size
• The reflectance is 1 at infinite frequency because there is no time for the mass to move before it is pushed in the opposite direction

In summary, the mass becomes a rigid termination at infinite frequency, and a free end (no termination) at zero frequency -- a ``dc blocker''.