That's an interesting line of reasoning.
It suggests that Bitcoin can only succeed if no such attackers exist.
Bitcoin can only succeed by growing larger than all attackers.
Maybe you and Peter Todd need to get in a room:
"Nifty paper proving what we knew already: w/o a blocksize limit there's no PoW security -> death of Bitcoin."
http://t.co/VPsgVkdzj9(
https://twitter.com/petertoddbtc/status/564934207487897601?s=03)
Since his tweet misrepresents what the paper says, it seems to me that he's irrationally entrenched in his opinion.