The part I really don't understand in this debate is that most people who care or claim to care about sound quality don't use an iPhone to play their music, or they use some sort of DAC because it's "better". For those people, the lack of headphone jack doesn't make a difference.
For the vast majority of iPhone music listeners will use the headphones that come with their iPhone.
At the end of the day, I feel like this is very comparable to when apple dropped the floppy drive from the iMac, dropped the CD/DVD player from its laptops, switched from 30 pin iPod connector to lightning. People are all upset and up in arms about it, announce the end of Apple again but in the end, it's a move in the right direction. In this case, either wireless audio (it was recently announced that wireless headset sales have surpassed wired headset sales for the first time), or lightning adapted/fancy usb dac!
FYI, this is the $9 adapter that will come with every iPhone 7:
http://www.apple.com/shop/product/MMX62AM/A/lightning-to-35-mm-headphone-jack-adapter
And this is a list of neat headphones that work with the lightning connector:
http://www.theverge.com/circuitbreaker/2016/9/7/12839722/apple-iphone-7-headphone-jack-lightning-cable
My 2c,
Alex.
EDIT: oh, and the old "what would Steve Jobs do?" really? Many stupid products have been shipped while he was at the head of Apple, that's not a Steve thing. I'm pretty confident he'd have been onboard with wireless everywhere, he hated cables!