Why do Korean ahjumas or ahjummas have curly hair?

So I asked kimchi boy: why do 99.9% of ahjummas (aka korean ladies who are .. older) in Korea perm their hair? It was as if all ladies went to the same hair salon to get the same exact hairstyle. 

I am not sure whether he was joking but he said that there is actually a sad story behind it - many of them are from post-war period and in those days, people were poor and they had to perm their hair so that they don't have to wash it so often and it was easy to maintain (it was the cheaper option). This does not make sense to me because.. Don't you have to pay money to get a perm -.- anyway he said that a perm is the cheapest in a hair salon, and sadly, there are a fair majority that think they actually look nice with permed hair.

Is this true?