Proof of Work criticism

As we remember, the Proof of Work was born in the long past 1993, in the cryptographers' family; parents intended it to become the defender from DoS attacks and spam. However, it received an offer it could not refuse by some anonymous with Japanese accent: to become a basis for distributed timestamp server. The scheme seemed simple: network nodes "vote" for their version of transaction history by introducing their computational powers into calculating "rare" hashes. The version that gets the majority of votes is accepted by all nodes as the reference version.

It will be incorrect to say that Satoshi was the first to think about using PoW for the digital currency. The idea of "reusable proof-of-work" had long been hovering among cryptoanarchists (and was implemented at some point, partially though), but it never got popular in its original concept.
The RPoW concept by Hal Finney proposed the "RPOW-tokens" to be inherent values (coins), while Bitcoin uses PoW only as a way to reach some distributed consensus (on the subject of which blockchain version should be correct), i.e. approved by the majority. This was the principal idea of Bitcoin that worked out.
Hashcash concept was selected as a proof-of-work scheme, and the SHA-256 was chosen as a computed function. It was the most popular hash function at that moment (2008). Most probably, the key factors were the simplicity of Hashcash and the 'commonality' of SHA-256. Satoshi added the 'difficulty factor' to the Hashcash (increasing or decreasing N - the required amount of zeros - depending on the number of participants) and, it seemed, secured clear decentralized future for everyone. Still, what happened later happened: GPU, FPGA, ASIC and even decentralized cloud mining.
There is no consensus on notion that "Satoshi (could) had foreseen" all this bedlam or not, but the fact remains: in September 2011, the first cryptocurrency that utilized a principally different PoW function appeared. Tenebrix used scrypt instead of SHA-256.