Anyone who uses the argument that Graphical is pronounced with a hard G sound needs to think about how they pronounce other acronyms, like SCUBA, NASA, LASER, SONAR, POG, SIM... the list goes on.
It's flattering that you think anybody knows what all of those acronyms actually stand for. I'm semi-certain of NASA, the rest could just be made up for all I know (as a non-native English speaker).