It's strange how seldom Eastern Christianity pops up in the West. For many years, I never heard of the Eastern church or realized its theology was different, and I took the Western church to be default Christianity.
Partly that was strategic, because I lived in the West but also because Western Christianity seems more influential on the world stage (via US imperialism) and also more evangelical and potentially damaging to atheism, secularism, and philosophical naturalism.
Similarly, I generally ignore Judaism, because that religion is relatively harmless. If the Eastern church is an ancient, pragmatic form of self-help therapy, it's not as obnoxious as the more literalistic and doctrinaire Western evangelical churches.
This is why atheists focus their criticism on fundamentalist religions, not just because those are the lowest hanging fruits, but because they're the most dangerous and obnoxious.