- As the transaction rate increases, fewer and fewer people are 'peers' (any more than a debit-card user is a 'peer' in the SWIFT system when they get cash from a machine.) The more they throw up their hands and just use Multibit or Blockchain.info, the less they know or care about 'P2P' and decentralization.
I don't see why people see this as an issue. Even Satoshi knew and accepted this would happen:
Long before the network gets anywhere near as large as that, it would be safe for users to use Simplified Payment Verification (section eight) to check for double spending, which only requires having the chain of block headers, or about 12KB per day. Only people trying to create new coins would need to run network nodes. At first, most users would run network nodes, but as the network grows beyond a certain point, it would be left more and more to specialists with server farms of specialized hardware. A server farm would only need to have one node on the network and the rest of the LAN connects with that one node.
What has made humanity so successful as a whole is specialization. For example, I study computer technologies, but ask me to design a house or to sell a product or to do the accounting of a business, and I will fail miserably, because none of that is my speciality. So, I don't get why people get upset when they say Not everyone will be able to be a miner. Well, of course not. Not everyone is able to do everything, and specialization is a good thing. And while people may think that this leads to centralization, the truth is that miners are not a single entity and are still many of them for this to be avoided.