I'm fairly new to this message board, I've been reading it through for a couple of weeks and have yet to post, but I thought I'd weigh in on this issue.
While it is certainly true that converts do bring baggage with them into the Orthodox Church, it is by no means the only way such baggage enters into the Church, nor is it the predominate way. Converts are often attracted to Orthodoxy because it offers them a cultural experience outside the American norm and are often willing to conform to the cultural norms of the Church they joined, but their American mindset is rarely abandoned. What causes greater problems (i.e. protestantization) is the general cultural influence of the West in general, and the United States in particular. This effects both convert and ethnic orthodox alike, perhaps having a greater impact on the ethnic Orthodox on account of their failure to realize and guard against this tendency -- the problem is not converts or 'cradle' Orthodox, the problem is Americans, regardless of how many generations ago their ancestors came to this country, and from which country they came.
America has a mindset of 'rugged individualism' which came from large open spaces and the era of 'Manifest Destiny;' a mindset which has become an integral part of American religion: Jewish, Moslem, Protestant, Catholic, and Orthodox. This mindset tells us that we can all be our own lords, our own theologians, our own Patriarchs, Bishops, Priests, Popes, Pastors, Rabbis, Imams, et cetera. It is the mindset that has created reformed Judaism, liberal Islam (not that these two are bad things, or at least they're than what they started with (for the very reason that they're watered down)), but it also created thousands of Protestant denominations from the small handful that came out of the Reformation, it is the mindset that gave rise to the modern individualistic Catholic Church in the United States, which is a thorn of anti-traditionalism, disobedience, and at times schism, in the side of the Papacy, and this is the mindset that leads to the forming of numerous schismatic orthodox churches, over minor and irrelevant squabbles about politics and pietistic issues of insignificant popular custom.
If one goes to the old world they see, with few exceptions (e.g. the 'True' orthodox Church of Greece (one of the more westernized of the Orthodox Countries, with strong modern democratic influences)), Orthodox Christianity as a natural element of their culture, the concept of breaking from the Church and forming their own sect is completely foreign and incomprehensible -- inconsonant with their traditional Orthodox views. To these faithful Orthodoxy is more than a religion, mindset, or worldview: it is a way of life. The Church cannot exist apart from their cultural experience; however, the Church is the defining element of their Culture. The problem in this country is that to maintain the orthodoxy of the Church, we need a solid cultural connection, not just a philosophical or theological one; unfortunately, this connection is tending to be replaced by the American pseudo-culture of individualism.
I say this as an American of many generations, and as a convert to the Orthodox Church, aware not only of the baggage I brought to the Church, but also of the even more damaging influence of American ‘culture’ and destruction of traditional Orthodox Cultures.