Firstly, you do not know it was 10,000 gallons. Nobody has even attempted to accurately quantify it, but 10,000 is a happy number that everybody likes to use.
Secondly, the vast bulk of the jetfuel, whatever the quantity, was consumed in the fireball. Liquids quickly decelerated from350 knots to 0 are atomized. It there is a source of flame present, that atomized fuel ignites and forms a fireball. It's common, and recorded on film.
Thirdly, as pointed out by Kevin Ryan who worked for Underwriters Laboratory at the time but was fired for speaking the obvious truth, the towers met the NYC fire code, and so did the office furniture within. As Ryan mentioned before he was fired, the fires observed were not nearly high enough in temperature to weaken the steel.
Other high rise fires that have burned far more intensely and for much longer periods of time confirm that general fact.
OMG, these NISTIAN cult followers believe all manner of nonsense, as long as political appointees lay it out for them.