You're absolutely right - USB-C is easily the way forward.
It just seems so odd to me that Apple are causing problems for their own customers and contradicting their own remarks.
Firstly, if you're going to tell us that the 3.5mm jack is obsolete, old technology, why then include it on the MacBook Pro?
Secondly, if you're going to release Lightning headphones, why not then have at least one lightning port on the MacBook Pro?
Considering every one of the billion iPhones that have been sold have a USB-A cable, why not just add a Lightning to USB-C cable in the MacBook Pro's box? Or, even better, why didn't they just design the iPhone 7 to use USB-C? Then you could charge the MacBook Pro from the iPhone charger and vice versa.
mac's have multiple uses. Some edit audio for film with them, some record things in the field etc.. At the end of the day keeping a headphone socket is not such a big issue in terms of space available. I think they thought that the iphone is smaller with less room to play and is more of a single use in terms of audio for most people. (not that I agree totally as many people use it for music stuff). I think it was just a tradeoff between space, future use etc..
Also mac's have relatively small sales compared to iphones so if you want to retrain behaviour your probably going to focus on the iphone.