Again, what makes you think the phone won't launch with a wired headset or support wired headsets? It just won't support 3.5mm.
Do you use Apple's bundled headphones? More than that, are you happy to pay through the nose for another set lightning-compatible headphones when they inevitably break? Why should we have to pay for adapters to conform to Apple's proprietary formats when the alternative is maintaining the currently existing, universally accepted, perfectly functional 3.5mm jack?
I don't want to pay for a lightning-to-3.5mm adapter and then have to carry that around with me everywhere as another thing that can break.