What is the point of this?

at the factory i work at there are fire extinguishers by all the exit doors, however my saftey supervisor told me the only time u should use them is to get to a door to get out of the building. what gives? if i could get to the fire extinguiser then obviously i could also get out the door since thats where the extinguisher is located.... am i missing something?? it jus seemed weird to me that he said we wud only use them to clear a path to the door?