Answer:
There was a few reasons to this. Overall, the shah was 100x times better than the rulers we have today but he still had his flaws.
Westernization, many Iranians were still conservative during this time and some did not appreciate his changes. He was very friendly to the west and US culture heavily influenced Iran during this time.
Absolute monarchy, just like the current regime, he was a dictator. His word was the final say and people wanted elections and democracy. He was also known to crack down political opponents quite harshly.
Essentially what we ended up with after the shah is a regime with all the BAD traits of the shah (political crackdowns, dictatorship, etc). But with none of the good traits such as modernization, growing economy, social freedom and better international relations.
Explanation:
Hope this helps!
