This always attracts pedants whining "the creator said to pronounce it like jif!" and it's like, OK,
A) That's an appeal to authority, one of the best known logical fallacies
B) The creator of Mother's Day spent over 30 years trying to get people to stop celebrating it, but too bad, I'm still gonna wish my Mom a happy Mother's Day, you know?
it's not an appeal to authority, if the choice was his, not ours, to begin with. Tons of acronyms have letters that are pronounced differently. It could be arbitrary because an acronym is its own separate word.
Divers don't dive oonderwater with their scuba gear. And when they take a camera with them, they don't get the pictures saved as jaypheg files.
The choice can be arbitrary. Since it is, the creator gets to decide. Like whoever discovers a new species of creature gets to name it whatever they like.
^^^this. Nobody is "wrong". Say it how you want to. Either way is fine. But get all cocky and tell me I'm wrong for using a soft g and you better be able to defend that assertion, because I've heard every argument for why a hard g is the only correct way to say it and they're all bs.