Personally, I don't see a reason for getting rid of it, but I will wait to see how they explain it to see if it makes any sense. As for lightning sounding better, it will depend on the headphones and the lighting adapter (DAC/amp) you use. As was already mentioned, you can use an external DAC with a lightning adapter already, so this isn't giving us something new from the lightning adapter, it is just eliminating the much more popular option.
For me, it would be a very minor issue since I rarely ever use the headphone output. I currently use Airplay, Bluetooth, or a Dragonfly DAC paired to the current lightning port (much easier to access with some cases I use). I know I am the exception to the rule, but each person will have to make a cost/benefit (of new features) analysis before upgrading. It definitely doesn't sound like a smart move on the surface, but I will wait for Apple to explain before completely passing judgment.
For me, it would be a very minor issue since I rarely ever use the headphone output. I currently use Airplay, Bluetooth, or a Dragonfly DAC paired to the current lightning port (much easier to access with some cases I use). I know I am the exception to the rule, but each person will have to make a cost/benefit (of new features) analysis before upgrading. It definitely doesn't sound like a smart move on the surface, but I will wait for Apple to explain before completely passing judgment.