Fire retardant clothing isn't necessarily on every one's mind. Most of us don't walk through fires or even stand anywhere near them. On the other hand, there are every day heroes who risk their lives to save others on a daily basis. For them, fire retardant clothing is the least we can do.
Military, fire department, police, EMT and other public service personnel need all the protection they can get in their dangerous jobs.
Campers and outdoors people can also benefit from the added protection of fire retardant clothes.
Or even if you're just paranoid, it couldn't hurt to have that extra safeguard in place.
So go on, retard those fires. Better safe than sorry.