Actually, all of Adam's criticisms deal with the supply and demand of currencies, and they are pretty strong and damning as a result. In sum, the supply of Bitcoins is finite (despite a growing population) and the demand for Bitcoins depends on (a) confidence in Bitcoins as a currency and (b) consumers' ability to convert between Bitcoins and fiat money with little friction.

(1) Adam's point is not the unfairness of early adoption, but that early adopters control all the rents. Today's miners will control currency as it appreciates, but after a point (say, the supply of mine-able Bitcoins is exhausted) there is zero reason to demand Bitcoins unless they supplant paper money (very, very unlikely).

(2) I'm weak on my deflation theory, but I don't think the computer-purchasing analogy is 100% right. Instead of buying the computer with paper money, consider buying the computer with gold bullions during the commodity boom. Why buy that Macbook Pro with x bullions today if you can buy it with x-y bullions tomorrow? Adam isn't arguing that "deflation is bad," but rather that the supply of Bitcoins as currency will dry up as their value appreciates.

(4) You can't hand-wave this away. Consumers have confidence in US dollars because the Federal Reserve and U.S. government can step in during a crisis and back people's assets. There is no similar guarantee for Bitcoins once something goes wrong.

(3) Why is convertibility not a systemic problem? Lack of convertibility falls out of all the previous points! Why accept bitcoins for cash if (a) they're not backed by a central authority, (b) almost no one else accepts them as money, or (c) they will be obscenely expensive once the supply dries up?

I can't believe Bitcoins have gotten this far. They're a currency accepted by almost no one as payment, guaranteed by no governing body, and artificially supplied as precious commodities without the benefits of said commodities (Bitcoin engagement ring? 24K Bitcoin watch?). They're a great theoretical exercise, but their real-world value will trend to $0 in the long run.

EDIT: barrkel gets to the point when he/she says "the value of money is a product of supply and demand, no matter whether fiat or specie." The fundamentals of Bitcoins are such that (a) supply will artificially dry up and (b) unlike precious metals/commodities, there will be little demand for Bitcoins aside from use as a currency (or a Ponzi scheme).