I believe it's pretty much common knowledge that Iranians generally despise the current regime but here is a cut and paste from a quick google search: "According to Gamaan, whose surveys are the most reliable, around 80% of Iranians are against the Islamic Republic. 15% support it and 5% are unsure." Revolutions have started multiple times and been quashed by the IRGC. The country wants a change. It is not just the U.S. coming in and forcing it on them.
I have no idea whether the people as a whole want a democracy, but the most important thing is to get rid of the brutal theocracy that kills people at the drop of a hat for any dissent whatsoever and is completely adverse to U.S. interests on literally everything. There is no doubt we could strongarm a leader into place that is not an active supporter of terror and is friendly to the U.S. The Shah was a puppet of the U.S. and our biggest ally in the Middle East. But the economy got so bad and he was well known to be a pawn of the U.S. so they wanted a change. Be careful what you wish for huh.
About a month ago or so, this board was highly critical of the lack of military action when protestors were getting killed. It was like a revolution was imminent if Trump would just do what he said and jump in with help for the protestors. Now, it's a "fool's errand" to try and topple the regime. What exactly changed between now and then?