They have no other arguments any longer. The only remaining talking point they have is that if we raise the block size limit too much that it will result in centralization (without a clear definition for what this means).
So we don't have 1% orphan rates at 1MB blocks? So the orphan rates would not grow if we had e.g. 8 MB blocks right now? It really seems like they don't really have any arguments. You should really discuss this with other people (not if you're going to be closed-minded) before making slides that are incorrect (hint: Luke-Jr said something about one on IRC if I recall correctly).Of course orphans would increase if miners published larger blocks [all other variables held constant]. That is what my talk was all about! It is the risk of having a block orphaned that creates the cost. Do you see what I mean? If I'm a miner, why would I bother to make an 8 MB block if it had (e.g.) a 25% chance of being orphaned? I would only do so if it included enough fees to offset this risk. This is the essence of my fee market paper.
There were 155 orphaned blocks in Q1 2015 and 97 in Q2. The average orphan rate is about 1%. It is the fact that block propagation is slow that makes it costly for a miner to even attempt to produce an 8 MB block. I estimate that, given the current network propagation impedance, a miner would only be wise to attempt to publish an 8 MB block if it contained 3 to 6 BTC of fees (due to his increased risk of orphaning).
As block propagation improves, it gets cheaper for miners to build larger blocks. There is a natural balance that occurs without the need for a tight limit. This is how Bitcoin has always worked. The free market solves the block size problem without centralized intervention.
source: https://scalingbitcoin.org/papers/feemarket.pdf