That hockey stick is neutralized by reverse hokey stick.
Velocity of M2 Money Stock/Population https://fred.stlouisfed.org/graph/fredgraph.png?g=DPfD
Velocity of M2 Money Stock/Population https://fred.stlouisfed.org/graph/fredgraph.png?g=DPfD
Saying that velocity is falling when supply isn't interesting or relevant. The question is whether supply is growing in excess of demand (as ever).
Also, you are wrong about prices not increasing "in reaction to possible buyers". If we lived in the fabulous world of rational expectations and flexible prices moving instantly but we don't. Understanding why this isn't the case, ironically, is why we use monetary policy/inflation targeting.
If prices would always increase when money stock increases, velocity of money would not change.
not Population/Velocity of M2 Money Stock like you did.