It's harder if you want to listen to something on your laptop for a minute instead or on the phone. It's also harder when the phone is in your <front/back/just the wrong> pocket and because it's just in the wrong orientation for the BT to work your audio cuts out.
> Bluetooth is easier than plugging in headphones.
Until it isn't, like needing to re-pair the devices, keep them charged, switch between multiple devices, etc. It's a hassle that I don't want to have to think about. I've got bluetooth headphones, but I never use them because they're a pain in the butt (and don't work with everything I want to use headphones with, anyhow). I don't understand people that are for removing functionality from their devices.
My iphone losing the audio jack would be a major inconvenience. I would have to carry multiple headphones, and also potentially bigger headphones since they will need to do more (blutooth, DAC, etc). Frankly, after having owned pretty much every iphone and ipod model since the begining, I will most likely be looking for an alternative.