Iran is most definitely a bad actor. Not even going into the regional problems that they produce for 3rd party actors, including our allies, and just keeping to things that they have done to the US, they are definitely an enemy.
They funneled weapons, technology, and fighters into Iraq. The most egregious example of this are the EFPs, an extremely deadly form of IED that killed Americans in Iraq.
They have launched cyber attacks on Saudi Aramco and the US stock market, and potentially others.
Their government continues to needle us at every turn, actively pursuing nuclear weapons.
I fail to understand how any reasonable person can think that they are "good guys." Any explanation of this position will invariably involve, "But the US!..."