People are blaming the government for poor maintenance and the sanctions against Iran that prevent the country from upgrading its air fleet. Iranian airlines have increasingly turned to Russian aircraft, which don't have the best safety record in the world.
There have also been a number of jokes satirizing Iran's air safety record making the rounds by email:
“Please respect the Islamic hijab at all times, even when you’re thrown from the aircraft. For emergency, a kafan [a white shroud that is used for burying the dead in Iran] is under your seat. Please remove it and wear it after saying the Shahadatain [testimony that there is only one God and that no one deserves worship except Allah] and a prayer for the health of the leader of the revolution."
“In case you need a tissue to dry your tears, you better bring some because we don’t have any."
“In case the cabin depressurizes, a headband will fall on you, where it's written: ‘May my life be sacrificed for the Supreme Leader.' Immediately put it on and wrap it around your head in the style of a basij. While you're chanting the name of the Imam Hossein you’ll be thrown out from the emergency doors."