Huh, was expecting the article to be about different meanings of centralization and how Bitcoin doesn't meet all of them -- to use Vitalik Buterin's terminology[1], it's not logically decentralized (being ultimately based around a single consensus ledger). Instead it's claiming that Bitcoin isn't politically decentralized like it claims to be.
[1] https://medium.com/@VitalikButerin/the-meaning-of-decentrali...