As a historian, I find this topic very interesting. I would say that, on a fundamental level, conditions in the east and west were quite different. On the surface it looks simple enough--the east has seemingly more government involvement in the Church, and in the west, particularly after the Papal Reformation of the latter half of the 11th century, the Church has more involvement in the secular world--for although Pope Gregory VII and his partisans rallied for the Church to be free of secular control, the papacy more and more, from that time, exercised involvement in secular affairs. A classic case of this, I think, is the Norman invasion of England, where the pope blessed William the Bastard to invade England and seize the crown for the sole objective of bringing England more firmly under papal control. This was illustrated by a papal anathema on Harold and anyone who fought for him. This is, in my thinking, the papal version of investiture, with the pope claiming the right not only to decide which bishops rule where, but which kings. So, in this way, Gregory VII was more wrong than Henry IV from an Orthodox point of view. "Lay investiture," not only under Henry VII, but centuries before that, could be a bit of a problem, but, following the Roman imperial model also used in the east, where there was a symphonia of Church and state for common ends, and bishops were not only church rulers but imperial officials, Henry IV was more justified. Of course, I have my biases. But I see in Gregory VII's resolution of this issue the beginning of future problems in the West resulting from the division of the sacred and secular. Instead of symphonia, there is discord. Was it all incense and roses in the east? Certainly not. Many of the eastern emperors were thugs with a penchant for strange theologies, but I think the east today turned out differently culturally, politically, in part because of this emphasis on Church-state cooperation rather than antagonism. One can debate whether "different" is better or worse, of course. I won't do that here because it opens up a complicated can of worms.
In sum, there were different forces at work in the east and west to get Gregory VII and Henry IV and their eastern contemporaries to the point in which they lived and worked. Different concepts of government and ecclesastical power, different traditions, different laws and canons and, by that time, different cultures.