It would be fine that the government shoots all US dollar holders in the foot by inflating their currency, the value of bitcoin relative to dollars would always increase, because the US Dollars would asymptotically approach zero value over time, as it has been. The bitcoin I worked hard to earn would retain their value. And the burglars would use their old fashioned tools to pilfer trillions from all Dollar holders, and will be forced to yet again shout: "darn" when they figure out they are only stealing from their left pocket to put into their right pocket. A waste of time.
Also known as taxable capital gains.
However, if he sells bitcoins in the future, he will be forced to pay capital gains taxes on the difference in price between when he received the bitcoins (and paid income tax then) and when he sells. If he sells at a loss, he can use his losses to offset his income tax.
This planet is in desperate need of a currency that can't be inflated by a select group of people not loyal to the interests of American Citizens. If a bitcoin ATM shows up nearby me, I would probably pay money just to help fund the cause.
And the government really does not levy the tax because "they are evil them", but because the governed society has certain needs that can only be fulfilled by common effort and it would be good to minimize freeridership. Of course one can discuss whether certain governmental activities are needed or not, but to abandon all government wouldn't do any good.