I agree with him that the block size limit is an anti-spam feature and should be treated as such, but the question is why (for example) 20 MB of spam is considered acceptable now. I see no good reason to allow 20x as much spam, when little to nothing has been done to control spam in any other way.
according to the new XT code today, the max would be 8MB, with doubling every 2y if 75% miners up-version.
you'd have to believe, for all the same reasons we've argued against for yrs, that a large miner would be willing to risk paying 8MB worth of spam tx fees for a prolonged period of time to try for the fuzzy goal of driving smaller miners out of business over an unspecified period of time, which may never come, and which comes at great risk to themselves from orphaning. given that the top 5 Chinese miners have already told us they are stuck behind the GFC with poor connectivity, i'm not sure how they do this mythical attack. trying to tap into the relay network apparently doesn't help. they've already told us flat out that 8MB is the max they can handle at this point and Gavin has demonstrated he is a
mature negotiator and conceded this metric to them unlike the Blockstream ppl who always just say "NO".
if a user wants to spam 8MB worth of stress tx's it will cost them 8x as much as today. expensive? maybe, maybe not. but at least they will be paying good fees to miners who will be happy with that. the real question is can they sustain that spam for any length of time. we'll just have to see. then the question is why hasn't anybody done that yet? i think it's also important to note that if someone tries this attack, it's reasonable to expect that miners and other users will
react. either by jacking tx fees even exorbitantly higher or blocking the offending ip address. point being, no one is just going to stand aside and watch a spammer destroy the network.