It's because the less units there are in the active supply, the higher the value of every unit.
Greedy people locking up Bitcoin just removes it from the active supply and raises the value of everyone else's savings.
In a Bitcoin world you cannot grow your stack without offering real value in exchange. There's no theft of properly secured coins, no money printing unfairly redistributing value from the poor to the asset holders.
The end result turns the historical truth that greed is bad on it's head. Greed is good on a Bitcoin standard.