Because it is just one letter. How is Graphics pronounced, without the "raphics"? I rest my point. There is only one Gif, pronounced with GUH and we know who that is.
In other news, American soldiers up in arms over being called ghees The acronym is pronounced jee-eye-eff. Short form, jeef CASE CLOSED
If you're going to breaking it up into two parts, like G-IF... then you've proven our point. LOL. The G in that case would be pronounced like 'gee' whittakers. However if you're not going to break it up and instead pronounce it as a single word, then you go with how the creators meant for it to be pronounced. Are you also so stubborn that you pronounce Dwyane Wade, Duh-Why-Ane Wade, just because that's how it's spelled? Or do you pronounce it Dwayne the way his parents meant for him to be called?
Ive always pronounced it Gif like gift without the t and it will be real hard to change my ways! Since we are on the subject, what about.. GUI... Pronounced like a word or spelled out? Gooey or G-U-I? IRC... same thing.. Irk? mIRC = Merk? or m-i-r-c? ROFLCOPTER!!11 = Roffle copter one one or R-o-f-l copter AI... A-I or latin flava Ai mami.. JPG... do we go ahead and say J-peg even though it's only JPG?? or is it actually Jipeg?? or is it just Jay peeg?
The creators wish is pretty much irrelevant (especially since it's an acronym and not a word, they created the acronym, not the pronunciation). Even if it was a word, the native english pronunciation is the hard G sound. Once a word is "anglicized" that frequently becomes the accepted pronunciation. For example, people produce the word "forte" as "for TAY" even though anybody with rudimentary french pronunciation skills knows the "e" is silent, it should sound like "fort". Same with "intelligentsia" (pronounced with a j in english, but in Russian, where it game from, with a hard g). So, you jeefers will have to put up with a losing battle and the "will of the creators" for now....
Actually, the french word is fort, not forte, and thus is pronounced as for and not fort. And to dismiss that the creators of an acronym only creates the acronym and not the pronunciation is crazy. Just because a word gets bastardized and used often does not make it right. It might be accepted but not right.