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.
"Growing" implies a stage of being smaller, at which point such attackers can and will destroy it. How can anything grow if it is already destroyed?
I thought I already answered that.
http://bitcoinism.liberty.me/2015/02/09/economic-fallacies-and-the-block-size-limit-part-2-price-discovery/The good news is that the largest and most dangerous attackers tend to be slow (compared to the pace of software development) to believe that a threat exists, decide on the correct response to neutralize the threat, and effectively execute the response.
The bad news is that Bitcoins inherent speed advantage is diluted by people who oppose growth based on the mistaken belief that smallness is an effective defense.