I agree with most of the problems listed here; but am just as certain of there being long-term viability for alt-coins as I was of bitcoin several years ago. I

I agree with most of the problems listed here; but am just as certain of there being long-term viability for alt-coins as I was of bitcoin several years ago. I am surprised though that the author did not make, what to me, is the most obvious and strong argument for or against alt-coins, namely; `there can only be one--per hashing algorithm`. The problem with alt-coins that share bitcoin's mining algorithm is that they are inherently insecure; as bitcoin's hashing power can be used to 51% attack the alt-coins directly; which is inevitable if the alt-coin is profitable to mine, or if it threatens bitcoin's dominance. Consider an alt-coin that is less profitable than bitcoin to mine; people won't mine it. Consider again an alt-coin that is more profitable than bitcoin to mine; miners will hash the alt-coin until it is less profitable (profitablility is a direct correlation between hashing power and price-per-coin; as more hashing power chases a static amount of coins, profitability drops)--this dooms any alt-coin that both shares a hashing algorithm with a more established crypto-coin and does not solve any fatal flaw. For this reason, I think litecoin will have long term success; while feathercoin (et al) are doomed; bitcoin hashing power cannot be pointed at litecoin. Total network hashing power is very analogous to mass and gravity; like draws like in this regard, the more hashing power pointed at a block-chain, the more secure it is, the more peopel trust it, the value it will have, the more people will mine it. There is room for infinite crypto-coins, despite the authors hand-waviness around bitcoin competing "with the dollar and paypal"; fiat currencies have shown (to the most freshman of history buffs) to be exploited for the benefit of the elite at the expense o the masses; something a well-designed cryptocoin (bitcoin included) cannot be subject to. People will choose to use cryptocoins as their benefits become more viscerally tangible; and competing blockchains will forever come in and out; and some will stay. But, if you ever want to bootstrap your own blockchain; you must use a new hashing algorithm or it is doomed.