Absolutely true. "Introduction of double-spend and other corrupt transactions because you control a significant fraction (perhaps LESS than 51%) of the mining p

Absolutely true. "Introduction of double-spend and other corrupt transactions because you control a significant fraction (perhaps LESS than 51%) of the mining power" is a vulnerability for bitcoin that is NOT present in other forms of value. But "a majority of the users could redefine what is considered valuable" is a vulnerability (mentioned in the post I was replying to) of EVERY representation of value, and not a particularly interesting or realistic one.