> Somewhere have to start the transition

By removing every single legacy port long before there's anywhere near ubiquitous USB-C? Even USB-C cables themselves are more commonly sold as USB-A to USB-C. I love having usable DisplayPort/Thunderbolt, HDMI, and USB-A on my 2013 rMBP - I never need a dongle. If I went to a 2016, I'd need at least 3, every day.

> Prioritising thinness and weight over everything else

Battery life is certainly not the same, and the lack of a 16GB option or a faster processor is a well-missed loss.