Completely wrong. This implies that the entire network could be comprised of SPV nodes that trust a small, centralized group (miners) regarding the validity of the blockchain. That is not a trustless system at all. It means that miners can level endless attacks on the entire userbase, from double-spending to transaction censorship. This situation is analogous to banking customers (the bitcoin userbase) depending solely on central banks (miners) to uphold the integrity of the system. It doesn't work in the real world and it won't work in bitcoin.

Non-mining users and miners have competing incentives. Miners are only concerned with profit -- historical attacks (withholding, double-spend, tx censoring) support that. The only checks on miners' incentives to attack other miners or users are 1) other miners (who might control enough computing power to prevent computing power based attacks) and 2) non-mining nodes (who might control enough nodes to prevent Sybil attacks). Past that, miners are presumed not to be honest (they have clear incentives to be dishonest), and will steal everything they can. Non-mining nodes are therefore essential to keeping miners honest, by making it too expensive or difficult to mount certain attacks against the userbase.


By definition, nodes reduce centralization. Since every node must receive and process every transaction in every block, they are the "peers" in the p2p network. They are what gives meaning to the word "decentralization." If miners (a much more centralized group than non-mining nodes) control all nodes, then the entire userbase is at the mercy of a group that can collude against them.

That the number of nodes, or a given proportion of nodes, can be obfuscated in the short term has nothing to do with that. It doesn't matter that you can't have a clear picture of the node software people are running, nor of their intentions....what matters is that without peers, bitcoin becomes a network based on trust.