Actually, while frustrating because of incompatibility with oversized plugs on some accessories, the recessed jack is a very good idea.
The biggest point of failure in a small audio device is the headphone jack, because of strain from its surface mounting, which ultimately breaks the jack's connections to the circuit board. This kills the device prematurely.
By recessing the jack, it is no longer subject to the stresses of having a tab right on the edge of the device, and any lateral force applied to a headphone connector is relieved on the case of the device itself, rather than on the weak connection to the delicate internals of the device.
The L-shaped connector, in comparison, is an inferior approach.