Monastic celibacy is a given, a traditional norm. No one disputes that.
Orthodox do require celibacy of bishops and of clergy who are unmarried at the time of their ordination, or who are widowed after their ordination.
No man may be a bishop who is not celibate. He may, however, have been a married priest, whose wife predeceased him. A widower priest may be a bishop.
The Orthodox Church, however, does not mandate celibacy as a norm for all of her clergy. That is the difference. While Rome may *allow* married men to be priests, the actual working out of that is a very small minority with roles largely as supporting clergy.
Local traditions varied, and I'm sure various historical texts can be brought forward to suggest or perhaps even clearly indicate that priestly celibacy was the local tradition of a particular place for a period of time. But since the Quinisext Council in 692, the present practice of the Orthodox Church was codified by Council, and later ratified by further Council.
The Gregorian reforms were a unilateral change of Ecumenical Tradition. This is the objection of the Orthodox.