Jet A and gasoline are completely different fuels, with different flash points, composition, combustion properties, etc. They have a completely different amount of refinement from the crude stock they both started as, etc. Jet A is actually kerosene.

I fly full scale planes with 100LL and have never heard of or seen jets at the airport use gasoline or 100LL. And you wouldn't catch me anywhere close by if some knuckle head tried to. But anybody that flies a jet (at least full scale) knows you just don't do that anyway.