Pillow fights are a symbol of sibling hood and being children. Siblings often fight for things which are not to be fought for, for matters which are trivial in nature. These pillow fights are the main reason why a pillow maker can never be out of business.
In old times after getting up from bed, protocols would dictate that beds be made immediately. Children would follow that rule to the toe, but once a pillow fight began it would result in cotton flying all over the room. Though many like such things, personally I dislike it.
Pillows are nice and comfortable soft things made from cotton and to buy a pillow now a days costs a lot of money and anyone who allows their kids to indulge in pillow fight, need a lesson in parenthood themselves.
Pillow fights looks good in movies, but in reality pillows look and feel good when they are used for sleeping or for resting.