I also wanted to add a couple of points that I didn't get to in the Twitter thread.
Economics. Blockchain technologists seem to overestimate the extent to which new insights in economics are needed to understand cryptocurrencies and blockchains, as opposed to applying basic principles from economics and game theory. For example, a recent paper shows that thinking about miners and attackers in terms of stock and flow exposes important limitations of the security of Proof of Work. [1] I learnt of many other such examples at a recent conference on the economics of blockchains. [2] So I think a lot of the "cryptoeconomics" hype is misplaced.
Privacy. It's often taken for granted that decentralized architectures will improve privacy. This seems obvious given everything we've learnt about Facebook, but a better way to think about it is that decentralized systems exchange one set of privacy problems with another. I coauthored a paper a few years ago skeptical of the "decentralization ==> privacy" story in the context of social networks [3], but I think many of the arguments in that paper apply to blockchain/dApps that are being built today.
[1] http://faculty.chicagobooth.edu/eric.budish/research/Economi...
[2] https://bfi.uchicago.edu/events/cryptocurrencies-and-blockch...
[3] http://randomwalker.info/publications/critical-look-at-decen...