Koreans don't put fan death on some kind of nationalistic pedestal of overdramatic belief systems that make you Korean. If we wanted nationalistic symbols, we already have plenty---starting with Dokdo (a.k.a. Takeshima, but don't utter that word in front of a Korean), the "East Sea" (more commonly known as "Sea of Japan"), and... but I digress.
Koreans believed fan death because their mothers did, and then their mothers did, and also the 9 pm news used to say "Yet another person found dead next to a fan" every summer, because in a hot, humid country of 50 million people someone is going to be found dead in a hot day next to a running fan.
How could it be a "national identity", when the very concept that some people might not consider sleeping-next-to-a-fan as deadly was beyond people's imagination. (Remember, it was time before the internet.) Now, thanks to the internet and everything, (I hope) most Koreans know that "Fan Death" is a silly urban folklore. We even scored our own Wikipedia entry. Nice.