In the past, when Apple removed certain hardware (floppies, CD drives) early, there was a clearly superior successor ready, and they were just ahead of the curve.

But the headphone jack didn't have a clearly superior successor, and from what I hear, still doesn't. The overall UX (and sound quality) of Bluetooth is worse, not better; it's tough to beat the utter simplicity of plugging in a headphone jack.

The only thing gained is no wires (and maybe some easier water-proofing, not sure). This is such a sideways move, it always struck me as a sign that Apple couldn't maintain Jobs's vision without him.