I've mentioned this before and will do so again here. What would the grievances be that would motivate a Reformation? There needs to be a sense that the Orthodox Church is so rotten to its core that there has to be something wrong with the doctrine, not just its administration (schisms over jurisdiction and political issues flare up all the time in Orthodoxy, afaik there are two pretty big ones happening now). It would have to be the kind of thing that just excommunicating a hierarch you disagreed with wouldn't fix. Aside from politics there are few reasons that I don't think Protestantism caught on in the East, and I'll set them out more fully below.
1) The governing structure of Orthodoxy is different than Catholicism. The East doesn't really subscribe to the "primacy" model that exists in Catholicism, where you have one bishop who based on doctrine is supposed to be in charge of the whole Church, and where breaking communion with that bishop means you are automatically outside the Church. The Patriarch of Constantinople did have a lot more power then than he does now, to be sure, but no one thought that he could be free from error or that if you were an out-and-out heretic if you didn't commemorate him in the liturgy. There was a lot more parity between the different bishoprics than there was between the papacy and Catholic bishops, and as a result conflicts over doctrine and practice tended to be different bishops excommunicating each other and eventually they or their successors settled their differences. Intractable disputes could be resolved without forming an entirely new Church.
2) The intellectual climate in the East was different than in the West. There had been no mass loss of Greek writers as there was in the West, and as a result no general cultural attempt to return "ad fontes" or to the original sources themselves to see what they really meant once they had been recovered. The Reformation was kicking off at the same time that Western authors were viewing other Greek texts like Plato with fresh eyes, and trying to distinguish them from previous interpretations that relied heavily on translations and intermediaries. It shouldn't be surprising that this would extend to a critical examination of the Scriptures, too, but that driving force doesn't exist in the East.
3) Theological arguments made by the Reformers rested very heavily on doctrines of which the East was wholly ignorant. Long story short, the Latin West had incorporated much of the theology of St. Augustine of Hippo into its theology in a way the East simply hadn't. It wasn't until much later that the East realized how little attention they had paid to him, and by that point some pretty stark differences of opinion had arisen, to the point where some Orthodox writers call Augustine "the Father of All Western Heresies." The Reformers took some of Augustine's ideas and ran with them, but those ideas were already foreign to the East, so there isn't any compelling reason for Easterners to accept them.
