Iran is no different from any other place in the middle east when it comes to one majority ruling a bunch of minorities. So there are tons of people who loved Qassem and tons that celebrated his death.
The majority are the classic Iranians, which are Persians. They are in charge. They are majority shiite. Then you got a huge percentage of Azeris, Kurds, Arabs, Lurs, Turkmens the list goes on.
The Kurds will split from Iran in a heartbeat and fight for America but after what America did to the Kurds in Syria, thats tough. The Arabs dont support the Persians. The Azeris do.
The other cultural divide in Iran is religion. There are tons of people who remember when Iran was very westernized before the 70s and the Islamic revolution and are against this ruling party. They are still Muslim, but they dont like the radicalized version of Islam that the Iranian government pushes.
So all in all, there are huge divides in Iran that the US could use. The issue becomes the same with Iraq and Saddam. Like as much as you hate Saddam and wanna get rid of him, he did keep the region relatively stable. If you go and force a regime change in Iran, you get rid of the Islamic Govt, which is great, but then what do you put in place that can stabilize the whole country?
