Why not do away with the age requirement? After all, as a recent American innovation, the bar mitzvah is surely ours to improve upon. Of course, there are many kids who will never choose to become b'nai mitzvah if left to their own devices, just as there are others who will surprise themselves by choosing to—and by accomplishing more than they think they could, without their parents prodding them at every step. If the bar mitzvah weren't set in stone at age 13, teenagers and adults could choose to read from the Torah for the first time when they were moved to—and they would get a real (rather than symbolic) taste of adulthood. So what if it takes some Jews decades to come around?... Doing away with the set age will lead to fewer b'nai mitzvahs—but they'd be more deeply felt. And that's probably a trade-off worth making.First, let's point out that no man is stopped from reading the Torah at any point in their lives, and that many people do indeed choose to give themselves late or second Bar-Mitzvahs at a point which is more meaningful to them. In addition, the kids who would choose for themselves to go ahead with a Bar-Mitzvah at 13 would probably get just as much out of it under the current system as well.
The problem, of course, isn't the kids' age -- 13 is still, even in this infantalized era, old enough and a good age for kids to begin understanding something about Judaism, responsibility, community -- but the parents' values and behavior. If the parents, even the most secular among them, shifted the focus away from the $8m. party and onto study, meaning, community, history, etc., the kids would get a lot more out of it. Unfortunately, the parents are too materialistic, too unfamiliar with Judaism, and too divorced from spirituality. This can be solved and indeed, many communities from Reform rightwards are finding that their congregants are thirsting for more spirituality. Some would argue that our society as a whole is finding more value recently in 'spirituality' and perhaps this too will find its way back to the Jewish community and its empty bar-Mitzvahs. By suggesting that people drop the Bar Mitzvah ceremony instead of taking responsibility for it, the author, Emily Bazelon, is simply too accepting of our society's faults.
Unfortunately, we live in a culture where people in too many cases never grow up and where the line between child and adult remains forever blurred. I think it's positive that in our Jewish culture there's still some kind of formal statement that kids are expected to mature, and what better age to make this clear than 13.