The micropayment channel scheme would address the tendency toward centralization, by rewarding non-block-generating nodes that propagate data, through compensation schedules negotiated on a one-to-one basis. The problem I'm pointing out is one of block generating nodes indiscriminately including zero/low-fee txs into blocks they generate, and thus increasing the bandwidth costs of the network as a whole. Paid data propagation via the micropayment channel scheme wouldn't address this.

The solution I'm suggesting is for the protocol to charge block generating nodes for the blocks they create, based on how much data is contained in the block, and distribute fees collected to other block generating nodes (proportional to their share of the network hashrate). This would not solve the centralization problem, but it would solve the problem of txs becoming a net cost to the block generating nodes as a whole. For this proposed solution to work, we need to pick a magic number to represent the minimum number of block generating number we believe the network needs to be sufficiently decentralized, and the protocol needs a way to reach consensus on the cost of bandwidth in relation to bitcoin. Multiplying these two numbers together would give us an estimation of the cost of bandwidth for the network per byte of data included in a block.