I think money is best used for buying and selling not hoarding, we get to see the value more when using it.
This my thoughts, wby?
Now to your question; I believe people hodl (hoard, in your usage) Bitcoin because they believe it's an asset too in addition to being a means of payment. As an instrument that has proved over the years that it can appreciate, it makes it easy for people to key into it. To be honest with you, a lot of those who buy Bitcoin aren't buying it for its tech. They're actually buying it because of its ability to give them a nice ROI. That's why they "hoard" it