That's the magic of human beings. Once the joke spreads to the point where the people who are in on it are flashing the symbol for the lolz, it no longer matters how it started or if there is no historical basis for the connection between the symbol and certain beliefs. The association exists now, however ironically.

Oh look, the guy who is racist is flashing the ok symbol. His buddy, who is in the same spaces online is flashing the symbol as a joke. How can we not make certain assumptions about the second person and what they think?