so i have a TINY science background (graphic artist for a science education company) and i'll try my best: the airflow PREVENTS any malfunctions by ensuring the heat dissipates. when air molecules heat up, they move very quickly and want to spread out to colder areas where there's less fast-moving molecules to bounce off of; heat will always want to move towards colder areas.
even a tiny amount of space will allow the molecules to spread out since they're moving very quickly and want to move to colder areas.
when these hot, fast-moving air molecules become trapped, they continue to bounce around and try to escape. without any escape route, and with a heating element present, these molecules will continue to move faster and faster and produce even more heat. this build-up of heat can affect the heating element as the surrounding air gets VERY hot and the heat cannot escape, thus reaching a temperature that can cause damage to the heating element.
does this make sense? i tried!