As someone mentioned, there are many reasons why, but I personally think greekischristian really nailed it. Add lack of motivation too. Many of the EO converts here, appeared to have been very motivated to search out and learn about various denominations before they settled upon EO. MOst people just aren't that motivated/have the time etc. etc. It's just easier to stick with what you know. It takes a lot of effort to to even discover there is such a thing as EO in the first place. I am not totally uneducated myself, and my first university degree was in Anthropology/Archaeology, yet I had no clue about Orthodoxy. Heck, while I was doing some backpacking in my early 20's, and remember stumbling upon an old, ?abandoned? chapel in the Plaka below the Acropolis in Athens, wandering in, and feeling the most amazing sense of serenity and peace. But because I was agnostic, (and often claimed atheism), and very ignorant of especially Christian faith (except in the negative), and frankly, lazy, I chose not to pursue that experience further at that time.
The only reason I ended up Orthodox is because I married into it. Shortly before I met my husband, I had started exploring religion and faith out of a personal need, rather than just out of cultural curiousity. Perhaps, had I really spent a lot of time at this, I would have discovered the EO on my own. I doubt it though. As it was I was embarrassed about my growing need and interest. Almost everyone I knew was anti-religious (especially anti-Christian - of course, in hindsight, I now understand how completely ignorant and hyprocritical this all was). I was not raised with religion; while my family was protestant in background, faith had not been practiced 3 generations, and then before that I am sure it was merely because it was the cultural norm. My family and some friends still think the fact I became a Christian, especially an Orthodox Christian, quite eccentric. They won't really talk about it as they figure it's none of their business, but you know they are thinking that my beliefs are so twisted (my atheist brother and sister-in-law wouldn't come to the baptism of either of my children because they think the western christian thinking behind Original Sin is so awful, and there is no talking to them about the difference in EO).
Anyway, my husband introduced me to the EO, although he rarely attended church (he did much more after I wanted to explore it further). I was baptised in 2002, and I am still incredibly ignorant about it, despite my attempts to learn more, and often not comfortable with it (as ethnically I don't fit in), but through my studies and my experiences, I know the faith of the EO is right.
But it is still an uphill battle. And I am a person that tends to be much more comfortable outside of my cultural sphere than probably most people. So if I find it difficult to surmount both the ethnic divide and cultural trappings of the EO, as well as the leap of belonging to an organized group of any kind, let alone one that believes in a higher power (although I recognize that for many people here, this part isn't so hard - so many of you seemed to have been churchgoers of some sort from childhood!), imagine how hard all of this is for so many others. Now, please do not get the impression that I think somehow Orthodox Christians are individually superior than others based on the following statement (just different - the world needs all kinds): I think many people here, at least amongst the converts, are of a different ilk than many. Bigger risk takers for one. Perhaps a little or a lot more rebellious than most. Some enjoy the intellectual challenge/exploration involved. Or maybe it just boils down to being slightly odd ducks that don't fit in amongst the "normal" mainstream anyway, so are comfortable climbing out of the "normal" box (if that makes any sense)? Wouldn't you have to be in order to get involved with something so different, when it would be just so much easier to wander in to the evangelical or mainline protestant church down the street, where culturally everything is familiar and the belief system is often just handed to you?
Sorry if my little ramble here is a tad incoherent. I'm tired, have baby brain, and cooked and prepared for 2 birthday parties this weekend. That, and I obviously do not have the ability to discuss theological issues with any authority - just the wish to learn.