Uncensorable digital currencies are being used to facilitate illegal transactions, and amongs all the blockchains, only ONE of them started with the intention of being a currency of some sort. Yes, there is a distinction between "blockchain" and "blockchain-based currency". Most of the other bullshit blockchain could not be used for that purpose.
I'm pretty sure a lot of people dismissive of blockchain, even on HN, would agree that the world is probably a whole lot better if Bitcoin is the only blockchain exist. It is a bit unfortunate that technical issue might prevent bitcoin of ever be a functional currency, but that is a different topic.