This is an interesting question. What's the answer?
Well, for my part its due to geography and time of day. Sunday school starts at the nearest Antiochian parish at such a time that getting the kids up and going would be a definite struggle. Plus, frankly, the building they have to use right now is not very handicapped friendly. This should change over the next couple of years as they are close to acquiring property of their own, but that property would place them even further away. Its somewhat unfortunate as its a great community and the priest is an exceptional preacher (he's one of the Campus Crusade gang).
So, we went to a Greek parish which is closer. The priest and presbytera are absolutely fantastic, as is the community. Yes, we've had to pick up a bit of Greek to keep up with the service, as its only about 50% English. I print out the hymns in English each week so everyone in the family can at least read them and understand the teaching. Once time permits, I'm going to make an effort to learn more Koine. We've started cooking more Greek dishes at home, etc. Why? Well, its good stuff. So yes, we have become a bit Greek. OTOH, when I married my Swiss wife, I became a bit Swiss (I was taught how to make killer fondue by her Dad). So now I've joined a community of mostly Greek folks, and I've become a bit Greek.
I think its important to remember that Greek, Russian, Romanian, etc., culture has been influenced significantly by Orthodoxy. For years before we became Orthodox we would use a Mediterranean cookbook to help plan meals for the fasts. Why? Well, because Mediterranean cultures were sufficiently influenced by Christianity that you find a lot of very complete vegetarian dishes. I find the degree to which men are involved in the Church refreshing, and that is, in part, due to cultural influences. So there is a lot to be said for adopting a bit of these Orthodox cultures. Over time, God willing, we'll see a growing influence of Orthodoxy in American culture (like there is residual Catholic influence - for instance the fact that McDonalds will not offer burger specials on Fridays, etc.). I think its important to remember that America's strength is in the amalgamation of many cultures.