I don't know, maybe you are right. But the condervatives, has proven that they are not willing to loose the power for any price. Maybe what they say is not just a bluff, and they are willing to take the people and the country down with them. So khatami's invitation to a confrontation, could actually result in a full scale civil war.
Just a historical clarification on Cuban missile crisis, which might also be relevant to the main discussion. I don't remember the exact reference, but apparently the new evidence that is coming out of Soviets show that if it was not for the decision of one Soviet general, the world had seen the scalation of the crisis into a full blown atomic confrontation. Specifically, based on pre-devised procedures, the head of soviets leading submarine has been supposed to launch its atomic missle towards US soil when facing the same conditions they were facing in the climax of the crisis, provided the go order of 3 higher generals. He asks for the permission and 2 out of 3 generals order the launch, but the 3ed declines... saving the world and announcing Kennedy the winner of this dangerous game. For side reference, a very good account of US decision making system in... [more at the permalink of the entry above]
It's true that the days of popularity of Khatami are over, but I think still if he uses a strong rhetoric, people will support him.
But that's exactly the point here: He is not a man of strong rhetoric. This is also the reason why his days of popularity are over. Just count the number of times people were hopeful that heould come out and say somthing. People don't just forget these things.