Good point. But even if you reveal ownership of any bitcoins "as soon as you have to" (oh yeah I sold some consulting overseas for 100 BTC ...), and pay the taxes on them, it still functions as a great way to protect your savings against inflation-happy governments, in a way that commodities and "inflation-protected government bonds" can't.

Ask any Argentinian if they'd like to have kept a stash before the Corralito.