The argument isn't that Mises is wrong, but that Rothbard clarifies him, and the Bitcoin community departs from both.
Rothbard in Man, Economy, and State: "People allocate their money among consumption, investment, and hoarding. The proportion between consumption and investment reflects individual time preferences." Three margins, not two. Hoarding is orthogonal. You can increase hoarding without changing time preference at all if you draw proportionally from both consumption and investment.
Non-monetary case: Crusoe can eat coconuts (consume), plant them (invest), or store them (hoard). His time preference is the ratio of eating to planting. Stored coconuts provide present utility: security, optionality, peace of mind. They're consumed as liquidity services right now, while depreciating and costing him the yield he'd earn by planting. If he stores 100% and plants nothing, his time preference isn't zero, it's infinite: he refuses to exchange present goods for future goods plus interest at any price.
On "plain saving": Rothbard says treating saving as a single decision that expresses time preference is wrong. Savings encompasses two distinct decisions: how much to invest and how much to hoard. Only investment expresses time preference through interest. Hoarding expresses liquidity preference under uncertainty.
The hodler enjoys present satisfactions: speculation entertainment, security, optionality. These are present goods consumed now. What's deferred is only the purchase of other goods, but that deferral isn't investment since no temporal exchange for interest occurs. The hodler who refuses to lend at any rate expresses infinite time preference, not zero.