I agree. I think another fundamental flaw with (current) cryptocurrencies is that they are all too computationally expensive to replace a simple, trust-based system. If you look at it from an economic perspective, the incurred losses from a trust based system (caused by it's inevitable and sporadic abuse) are probably still smaller than the costs caused by a (theoretically) abuse free system like ethereum. That being said, there might be corner cases where these additional costs are sufficiently small to make a blockchain-like solution viable - for example for very low volume but very high value transactions, like a settlement of financial contracts (bonds, etc.), ie. for any transaction, where an abuse of the system is extremely costly.