Great article. It's almost certain that 95-99% of the current cryptos out there will not survive long term.

Any thoughts on the tipping point towards mainstream adoption of cryptocurrencies as... currencies?

Right now it's simply seen as a speculative investment vehicle and not much else. IMO it won't be seriously used as something to pay for goods and services until:

1. Major adoption and stabilization
2. Top companies (Amazon, eBay, etc..) offer it as a mode of payment

It's kind of a catch-22. You can't really have one of these without the other. Here's hoping the tech continues to make progress and attract new people until it can fulfill its vision.