The Verge has an article today, which goes over Economists and their dislike for Bitcoin as a currency.

University of Berkeley economist Brad DeLong believes that Bitcoin will fail because the cost of producing a Bitcoin clone is zero. George Mason economist Tyler Cowen agrees, and adds a warning about deflation.
-The Verge, 12/31/2013

These views are fundamentally incorrect, and show a massive misunderstanding of the infrastructure that supports the blockchain. The cost of producing a bitcoin clone is... quite high, actually. Creating an alt-currency is a near-zero cost endeavor, but producing an actual clone of Bitcoin, with the mining/transaction nodes in place is prohibitively expensive, as is encouraging a wide audience to adopt the currency, and put it into use. The difficulty for crypto-currencies is adoption, not creation. Imagine it more like trying to start a new religion: the writing is easy, it's getting people to believe that's hard.

Paul Krugman writes:

I have had and am continuing to have a dialogue with smart technologists who are very high on BitCoin — but when I try to get them to explain to me why BitCoin is a reliable store of value, they always seem to come back with explanations about how it’s a terrific medium of exchange. Even if I buy this (which I don’t, entirely), it doesn’t solve my problem. And I haven’t been able to get my correspondents to recognize that these are different questions.

What Krugman should take a look at is Bitcoin's base value as being derived from the computational power and infrastructure required to manage the transactions and the blockchain. Every node active on the Bitcoin network adds value to the currency, in somewhat the same way that gold's value can be seen as a store of value because it can be used to make pretty jewelry.

Now, obviously no one would value gold simply on it's ability to be melted down and made into rings and necklaces, or serve as a conductive material, right? Two other key points go into the base value of gold: its rarity, and its ability to be used as a medium of exchange for goods and services.

Don't look now, but Bitcoin manages to meet both of those requirements as well, but is arguably far better as a medium of exchange, due to its ease of use in transfer.

Bitcoin does have a lot of issues facing it in the future. To name a few:

Wide-scale adoption. This is probably the biggest key to Bitcoin's continuing success. Its adoption is absolutely crucial to its growth as a medium of exchange.
Value fluctuation. This will stabilize as the market cap of the currency and adoption grows larger, and large transactions become less likely to cause swings in value.
Wallet icing. Lost coins can almost never be re-added to the system.

None of these are issues caused by knock-off alt-coins.