That's my issue. If BTC has value because it can be used to buy goods, what happens where everyone is HODLing and nobody is using it to buy goods? It will most likely see a continuous decrease in adoption and, as a consequence, a decrease in value because at that point you own a digital coin that is completely useless.
The main thing to realize is that money is useless for people if not used for exchange for goods or services. It is nonsense to assert that people will hold their bitcoin until they die. What's the point?
And now that I think about this, one solution could be to introduce a system in the Bitcoin protocol where a small, but increasing portion of BTC that are not moving from an address are transferred automatically to a "community address" for other users to buy, or maybe it goes to active nodes as a way to incentivize network security. The more you hold, the more BTC are transferred to this community address or to nodes.
This would solve the hoarding issue and would also re-appropriate tons of lost BTCs.
First of all, there is no hoarding issue because every bitcoin that is lost or not moving adds to the purchasing power of each unit. Given that bitcoin is a highly divisible currency, any "active" supply of it is able to satisfy all economic activities that take place in the world.
Secondly, we don't need socialism in bitcoin where the property of one productive person would be seized and shared among unproductive assholes.