The motive for creating the hoax would belong to Firefox supporters if you ask me. They’re trying to get their product’s name out and whip up some sympathy as being unfairly persecuted in typical environments. From the looks of the thread responses it didn’t work, even many firefox users were turned off.
OH NOEZ!! IT'S THE OPEN SOURCE CONSPIRACY!! IT'S THE COMMUNISTS WHO DON'T LIKE MICROSOFT!! OMG OMG OMG!! EVERYBODY RUN!!!
C'mon GE, lighten up. Some kid who happens to hate IE probably decided to go up against the teacher, caught hell for disobeying directions, and decided to get even on the internet with a hoax.
Firefox's name is plenty "out", and no Firefox supporter would intentionally launch such an inane stunt anyway; as you correctly pointed out, it's not very effective.
Seriously, GE, they're not -ALL- out to get you... just us ;-)
Oh, please....