The three principal, positive reasons why I believe people choose to be Orthodox: community, coherence and connection.
Community. Orthodoxy creates a powerful caretaking community. Little wonder that so many step into an orthodox synagogue and feel instinctively, here is the emotional core of what religion at its best. The shul visitor to shabbes lunch quotient, which I propose as a measure of a community’s fidelity to itself, is immeasurably higher in orthodox communities than in any other denomination.
Coherence. This is not only a feature of orthodoxy, it is the defining intellectual position. All of the tradition is essentially seamless. There may be opinions whose place we cannot yet define; some particularly outré speculations can be ruled out of court. But there is no degree of apparent discontinuity that would persuade the orthodox community that Moses, Rabbi Akiva, Maimonides and the Lubavitcher Rebbe were practicing essentially different faiths — or, as one modern scholar puts it, "Judaisms." Positing a grand fabric lends coherence that is sometimes missing when parts of Jewish history or thought are dismissed, or opinions explained sociologically rather than harmonized halachically. No believer needs to seek footing on a slippery slope, because everything is understood (with but nugatory exceptions) as an integrated whole. The twists of the oral law, its periodic seeming implausibilities, are kept from challenging the system by the certainty that contradictions are flaws in understanding, not in revelational content.
Connection, theurgy. Why perform mitzvot? Ta’amei Hamitzvot is, as Jewish philosophers have always recognized, a dangerous enterprise. That which has a reason can be invalidated by a reason. But if mitzvah is, at bottom, ratzon Haboreh, then nothing can be greater than its fulfillment. God wishes it. A mitzvah can make a difference in the fabric of the universe. The kabbalistic, theurgic amplification is that performing the mitzvah can make a difference to (or in) God’s self. How pale, by comparison, is the dutiful liberal explanation that the mitzvoth will make you a more sensitive person, a more caring person, someone closer to the history and destiny of your people. Of what power is such therapeutic encouragement beside God’s expressed will?
There are good reasons to choose orthodoxy. Now, why am I not orthodox? Ah, perhaps that is a question I will have the opportunity to elaborate another day.