Underestimate blockchain at your peril

Quite! but that's a problem with Bitcoin in particular. I was trying to point out mostly problems common to all blockchain-based cryptocurrencies similar to Bitcoin, not just implementation problems in Bitcoin.

The related problem for all implementations is that they have a horrible choice:

- either make transaction costs ridiculously high due to the need to lug around a massive database of all transactions ever -- which for practical replacement of real currencies would need to have new blocks arrive at least once a second, I'd guess, so it would be exabytes in size soon enough

- or make everything horribly insecure due to the need to trust someone *else* with carrying out the actual, netted transactions of many other people. And at that point you're back to trusting someone else not to run off with all your money, so, uh, what's the advantage of this over ordinary currency again?