Iran and future society

From my understanding of jafari, government should be a different entity that the ulema( religious scholarly class of islamic jurice prudence )

my question is, why in a society like iran ( or any society in that matter) have perversion like the current situation in iran, where the religion and government are the same (its not supposed to by khomeni's standards)?

the second part of this, is that is it possible to see future societies embracing each other in some way?