We are far from understanding the full sociological impact of the ba'al teshuva movement on the orthodox community. One paradoxical result is the reinforcement of communication and movement from orthodoxy outwards.
Consciously or not, the overt paradigms of the ba'al teshuva movement are precisely those of the open liberal society. Simply put, all commitments and ideas compete in the free intellectual marketplace. Thus, a prospective ba'al teshuva is asked to examine the possibly greater validity of traditional Jewish ideology over the ideology to which he currently subscribes. While works such as the Kuzari and other medieval philosophical texts may flirt with similar paradigms, it is clearly not in line with general Jewish tradition. As the paradigms of the intellectual marketplace become more widespread among the orthodox, it naturally provides fertile ground for defection from traditional Judaism.
If the ba'al teshuva movement is a generally pleasent adaptation to modern paradigms, we must realize that the very nature of the game also entails losing core constituents. Defection from othodoxy must be viewed in the same terms as disease - tragic on the individual level but unavoidable on the aggregate level. Accordingly, parents cannot usually blame themselves when a child falls ill. While poor role models will inevitably bring up religiously undernourished children, even the best role models will occaisonaly have casualties. As with our children's physical and mental health, we can only give them the best possible *chance* at wellness, but not wellness itself. Part of the maturation of orthodoxy in the Modern period will be acceptence of this fact. While we can and should attend to all the problems that result in defection from our ranks, we must accept the reality of the two-way street. Failure to do so is not just hypocritical but also simple-minded.
In fact, the only other option to accepting the marketplace model is complete isolationism, something that extremely few of us are really willing to consider. This would entail living in villages separated geographically and cut off from modern communication - something even the Amish are having trouble pulling off today.
As nuclear and extended families divide and redivide over religious beliefs and lifestyles, the knowledge that family members have different beliefs makes those beliefs more accessible. This is aggravated by the existence of thousands of ba'alei teshuva who have integrated into the heart of orthodoxy. When they marry in, they bring a host of non-religious relatives with them. While the beliefs of the gentile in the middle ages did not interest most Jews, the beliefs of your brother-in-law or uncle are certainly certainly provokes more curiosity.
We do not have to approve of the markeplace paradigm - we simply have to accept it as the necessary cost of participation in the modern world. As such, we must compete for the hearts and minds of all Jews, including our own children. A smart producer will never assume that he has a market wrapped up, nor will he presume to misrepresent a competitor. Mocking or simplifying other ideologies is a dangerous approach - while we can and should point to fallacies and weaknesses in other modes of thought, we should do it from a point of intellectual humility. We can only attack what we truly understand. By the same token, we should also not overestimate our own understanding of positions espoused by orthodoxy. Religion and philosophy are complex matters and should be treated as such.
On the positive side, the marketplace of ideas may serve a critical function for orthodoxy in Modern times. Through the long and bitter galut, all sorts of extraneous ideas and attitudes have attached themselves to normative Judaism. Exposure to, and competition with other points of view can only help us be more objective in seeking out authentic Judaism and discarding that which is ultimately wormwood. Here we are going deeper than the Rambam's famous dictum of accepting truth regardless of its source. Rather we look to the Maharal, who sees the authority of Beit Hillel coming precisely as a result of their ability to understand the positions of Beit Shammai.
Positive or negative, the marketplace paradigm will be with us for the foreseeable future. How we learn to adapt to it will have a large bearing on the long-term success of orthodoxy.