People are commenting this post and saying it is speculation, and until someone who directly was involved in these discussions shows up to comment, I suppose it is.

I have been in design meetings with Jony, and Scott Forstall, and many others whose decisions were micromanaged by Steve at every step. You can argue that a lot of Steve's design decisions were questionable; rich Corinthian leather skeumorphism, lickable Aqua widgets, brushed aluminum window title bars, but he owned them.

Steve and Jony would sit for hours outside of Caffe Macs going over designs. Steve would spend even more time inside the industrial design area going over prototypes. He would spend a couple of hours every week meeting with every software team that had user facing features. He had input on almost every pixel on the screen and every button/port/display/etc on hardware.

Once he was gone, the drift began. It was inevitable that focus would shift. Scott no longer had protection by Steve. Jony fixated on the new campus and things like watch bands. No one had Steve to rein in whatever impulse they had. Sure, people would ask "What would Steve do?" but we also had Tim Cook pushing to optimize production, lower cost of goods and increase margins.

Apple still has Steve DNA, but it continues to be diluted. You may disagree with Steve's vision and opinions, but it was strongly held and enforced. I feel almost everything about the last generation of MacBook Pros went against what Steve would have wanted and I am glad I wasn't there when those decisions were made.