why would I used an adaptor? For 1 I can't use the adaptor and charge the phone at the same time - I have to buy another adaptor to do this, which doesn't even work with the supplied headphones! Secondly I would have to unplug the adaptor if I want to use my headphones on my laptop, or my ipad. And finally adaptors break and get lost. Give me a 3.5mm jack any day over an adaptor.
This is quite possibly the worst idea ever to come out of Apple. It's not like it was an unused bit of tech like a parallel port. Every phone, laptop and tablet has a 3.5mm jack. This IS the standard, not lightning. It would have made more sense to make a slightly thicker iPhone for the new features, leaving the jack in place and increasing the battery size at the same time. A handful might have complained about the extra few mm of thickness, but there would be many more happy customers if they could get more than a day on a single charge and keep the 3.5mm jack.