The mullet haircut was very popular in the 90s. Almost everyone sported this hairstyle but it fell out of favor after the 90s. Between 2000 and 2014, I have only seen a few people who still have this haircut. Most people consider it unfashionable nowadays. But like all things, I suspect that this haircut will too become popular once again. Things that were not unfashionable several decades ago are fashionable again now.
I read that in 2010, the government of Iran banned mullet haircuts because they consider it a symbol of the West. I find that interesting because people in the West don't care for the hairstyle right now!