It's useful to look at why the comments were wrong though. In the Dropbox case it was because the user forgot the size of the market of people that didn't use Linux on their desktop or wish to periodically upload folders using FTP clients encompassed most of the computer-using world. With crypto it looks much more like the evangelists who've erred on the side of discounting the level of inconvenience of their solution to non-niche adopters (including bits which are integral, like transactions being irreversible, secure private keys being the only way of retrieving one's funds or contracts being code)