The few scraggly freaks who had always pronounced it that way probably shrugged and thought "Yeah, that's what I've always said." The rest of the world took the news like God himself had come down from Heaven and said, "It's pronounced 'Gesus Christ.'" Nobody was noncommittal on the issue. Even Barack Obama is on record that the official presidential stance is "Hard G all the way."
YouTube has thousands of videos which passionately scrutinize the subject. There are entire websites full of painstakingly elaborate arguments. You could easily lose an entire day trying to pull apart this Reddit thread alone. A common argument in favor of the hard G is that the first letter stands for graphics, not jraphics. Pretty solid reasoning. But here's one of the many, many, many comments out there defending the creator-approved "JIF" pronunciation:
SCUBA stands for "Self-Contained Underwater Breathing Apparatus." You do not pronounce the U in SCUBA the same as the U in Underwater. LASER stands for "Light Amplification By Stimulated Emission of Radiation." You don't pronounce the A in LASER like you pronounce the A in Amplification, nor the S as you do in Stimulated, nor do you pronounce the E the same as in Emission.