I on the other hand see wireless audio as the future, and a very near future at that. And I see it as a major improvement over having to plug in a wire tethering me to my equipment, or my equipment to each other. Not all improvements are as clear cut as going from the floppy disk to the CD-RW. Sometimes an improvement is about visibility, not just increased storage capacity. And there's nothing more versital than eliminating the wires. While the net result is the same whether going from floppy to CD, the more appropriate comparison is the loss of the perfectly good Ethernet port from Apple's devices in favor of WiFi. In fact, every single argument you make for retaining a wired 3.5mm connection for audio, I can make for retaining the wired Ethernet connector, something that affects me, and tens of millions of other Mac and iOS users daily.
I have none of the problems you seem to have with Bluetooth headphones. I love the freedom it provides at the gym, at the beach, hiking, biking, or just walking the dog. I love not getting tangled in my headphone cord when I'm sitting in an airplane seat and have to let another passenger out. I love not having to unplug from my laptop, just to stand up, or walk away from it for a second, or even just sitting on the couch listening to a podcast on my iPhone. In fact I can go on and on all day about how much more convenient wireless is for me than a wired cord -- despite some of the issues that Bluetooth still ha to address. For me, all those trade offs are worth it. Now you would have us believe that nobody wants that kind of freedom, and given the choice where all things are equal, people are always going to want to plug in their hardwired headphones because they already have an investment in them and don't want to be forced into buying a new pair regardless of the convenience it provides. And using this logic, nobody would have ever switched to Wifi from Ethernet. I bought the very first Apple AirPort which used a dial-up connection, and loved it so much I bought my 70 year old mother one. And you know what, it wasn't perfect, it had a lot of problems, and it certainly wasn't as efficient or reliable as Ethernet, or even my hard wired connection into my modem. When DSL came along the same thing was true. But it was worth every headache, and not just to me but tens of millions of customers. As a result the price came down, more people discovered the convenience, which led torpid adoption and improved technologies. And the mobile space continues to expand to the point where Apple decided to remove Ethernet ports, despite the fact the WiFi is not yet at the point where it's better or more reliable than Ethernet. It's simply more convenient. And that is the future of audio.
You say there's no reason to remove it, but I say there's every reason to remove it. Because it forces developers to improve current wireless audio technology to meet the necessity of needing another way to connect, and that in turn lowers the price of wireless audio connectors, putting the convenience of wireless audio in more consumers hands, and forces developers to step up their game to provide better quality, and more reliable devices. As a consequence, it also forces those same developers to offer better quality, lower cost, and more reliable Lightning solutions, which will ultimately better serve most people for anything more than just plugging a set of headphones into a jack and listening to sound. In fact it will likely improve that as well, offering better quality equipment at a lower price, and lower quality equipment at a lower price, depending on a customer's needs. Think about it, who better to chose the DAC for their headphones than then the manufacturer? In that way, Apple is only responsible for delivering the digital data of a sound file, and cannot be held accountable for the quality of the sound, or how their hardware may affect a third parties audio reproduction. In fact, that's the Apple model.