[carlosrg]

> If 51% agree on the legitimacy of the block, consensus is reached

I think this isn't entirely right, because he's talking about 51% of miners. The ones that actually incorporate the blocks to the blockchain and validate if the transactions are valid are the nodes (I might be wrong but that's my understanding). In fact this article fails to mention nodes at all, and nodes (for example people running the Bitcoin Core client at their computer) are what make the whole thing decentralized.

[doomroot]

For the most part your are correct. I think one distinction should be made. Economically active nodes are what matters not just any old node that someone has sitting in a closet.