Why are any Iranians upset?
If they didn't want to live under Sharia Law they shouldn't have overthrown the liberal monarchy that was rapidly advancing them economically and culturally until the 1979 revolution when the vast majority of them thought it a great idea to murder a large number of the citizenry then replace the Shah with a theocratic dictatorship. While I feel sorry for the women of any Islamic culture, I feel little pity for Iranians themselves, as on the whole they embrace radical Islam, and have only themselves to blame for all their economic woes.
Before 79 they were one of the wealthiest, best educated nations in that region. Now they're the exact opposite. Alhamdulillah?
They overthrown the liberal monarchy because they remember Mossadeq. They remember a lot of things as they are a 27 centuries old nation. Mohammed Mossadeq was their democratic elected president in early 50s
He was also a liberal and not religiously fanatic , in fact hard islamists didn't like him at all.
Guy was trying to find a new political way for the country, economy was doing well and he wanted to have good relations both with western and communist countries. He was a popular and honest president.
But then he nationalited oil production, under the idea of iranian natural resources belonging to the iranian people, not to British Petroleum and other western companies.
What happened next? Yes, economical blockade to make him fall. Didn't work.
So, what happened next? Yes, CIA killed him. Then, US and UK put that liberal monarchy that you said, the utter corrupt Sha and his criminal politic police, the Savak.
That's why iranians overthrown him.
Did they do a smart move promoting a radical and fanatic Ayatollah to the head of their nation? No, I don't think so.
I think wearing a hijab is not opressive, being forced to wear it is.
A young woman dying in a police station after being arrested for wearing her hijab wrongly is not opression, it is full blown murder.