I am making this post, not for starting a debate on whether intrinsic value is important or not, but as an experience of thought about why, from an Austrian school perspective Proof Of Stake can't work.
I do not want to debate whether the austrian school is right or not, I want you to evaluate if, given my premises I reach a coherent conclusion.
When an Austrian is skeptical about Bitcoin, he points out the lack of "intrinsic value" in Bitcoin.
Since I don't like this term that is vague, I will borrow the term "use value" of Mises instead.
An Austrian argues that Rice, Tabacco and Gold have a purpose outside those of a medium of exchange.
You can eat Rice, you can smoke Tabacco, and you can make Jewel with gold.
The use value makes the commodity highly marketable, which develop it as a candidate to become a medium of exchange.
Then, if this commodity is durable, portable, divisible, uniform, non falsifiable knows as "characteristic of money", it develops naturally as a medium of exchange.
There is no doubt about the "characteristic of money" in Bitcoin, which are higher than any existing alternative.
However, for the Austrian, the lack of "use value" of Bitcoin means that it can't develop as a medium of exchange.
But there is a clear use value of Bitcoin : Bitcoin allows you to insert a row in the Blockchain.
Even if Bitcoin is worth nothing as medium of exchange, inserting a row in a database that is global, can't be censured and can't be altered has a value.
This is the "use value" of Bitcoin.
As you know, such database would offer perspective for multiple industries, not yet exploited but soon will be. (justice, finance, insurance, payment and remittance)
The utility of the blockchain is rarely opposed, but if you admit its value, from an austrian perspective you also give "use value" to Bitcoin, since you can't insert without fees.
Surely enough, individually you can give no fees but if everybody do it, miners would more and more be reluctant to insert you, and this will be even worse when there will be no block rewards.
Even an altrust miner will make you pay the fees, because if he does not, he will loose money and then would not be able to pay the electricity bill.
Meaning that on the whole, fees, and thus use of Bitcoin will be mandatory to make the Blockchain lives.
And if Bitcoin has use value and the characteristic of money, then it will develop as medium of exchange.
So, from Austrian perspective, you can't admit blockchain utility without seeing Bitcoin as an emerging medium of exchange.
If you want to stay coherent and Austrian, either you deny blockchain utility or you accept Bitcoin as a kick ass medium of exchange.
Now, lots have been said about Bitcoin mining being "wasteful", and that Proof Of Stake would be "greener". (see
https://en.bitcoin.it/wiki/Proof_of_Stake and
http://bitcoinmagazine.com/6528/what-proof-of-stake-is-and-why-it-matters/)
I argue that from Austrian perspective, if a crypto is not "wasteful" (implying Proof Of Work), it can't have any "use value" and thus thrive as a medium of exchange.
Let's imagine a currency like NXT on Proof Of Stake. (It should be noted that I know nothing technically on NXT, but I just need a plausible name for sake of clarity)
You will mine a block with a % of your holding. IE, if you hold 1% of all NXT, you'll have 1% of mining the block.
Like Bitcoin, you would earn a block reward + transaction's fees.
Now my question is : why would a payer include a fee in its transaction ?
If there is no cost in inserting a transaction in the blockchain, an altruist miner would accept to process all transactions without fees. (for the benefit of the network and for protecting his stake)
If such is the case, there is no "use value" for NXT, thus (from austrian perspective again) it would not develop as a medium of exchange.
In turn, the "Stake" of miners would not worth anything, collapsing the network.
However when mining is costly (proof of work), if the miner want to survive without block reward, fees will be mandatory to pay the bills.
As the payer, Bitcoin is useful because it is needed to insert in the blockchain. As the miner, it is needed because it cost them real work to insert in the Blockchain.
Note that this explanation is also coherent with the labour theory of value of Marxians, which argues that gold is valuable because it requires work to extract.
I think for the austrians, which I agree with, the interesting point is the bitcoin and the bitcoin fractions and the relatively fixed amount of bitcoins in existence. Not the number of bitcoins, that number is arbitrary. The question is, can we be sure that the actual number is static, or in the case of gold, the fact that the production is small relative to existing monetary gold, and independent of governments. In case of gold, we can not know the volume, only that it is relatively stable.
From a money policy point of view, the mining is not interesting, it is enough to know that the blockchain guarantees that the bitcoin number can not increase. It is also good to know that there is a minining reward that makes sure the miners keep running without the need for a central manager.
The problem for austrians have been that the value has to start with the use value of a commodity, and gracefully transform into money. In case of fiat, the last transformation is from the gold backing that existed long ago, to the current free floating fiat. The rule is the Mises' regression theorem.
I think we have shown with the practical experiment that is bitcoin, that this theorem is wrong, because bitcoins have value and it started from nothing. Some might disagree.