Knowledge preceedes enlightenment. For example, Git is also green-friendly, and shares a virtually identical consensus model to pure PoS consensus designs. It’s just that “green-friendliness” wasn’t a design goal of cryptocurrency — creating a lasting store of value sans institutions, exchangeable pseudonymously over the internet, was.

As it were, pure PoS consensus suffers from the misfeature of not even having a quantitative fork ranking protocol — i.e. it lacks a way to objectively compare the truthfulness of divergent blockchains [1]. In PoW networks, cumulative hashing power can be simply and easily mathematically compared to produce cold, quantitative consensus. In PoS networks, there is no hashing power, and human intervention is required — just like Git.

Which begs the question, why do PoS networks even need a blockchain? I think we all know the reason for that, though — Git doesn’t have a hype train. Git just isn’t good enough at separating the general public from their hard-earned money.

[1]: https://news.ycombinator.com/item?id=27144921