The comment "15-inch Pros have enough thermal headroom to fit in quad-core Skylake processors..." is interesting. While the current offerings don't meet expectations set for the MBP... maybe this is a long play by Apple? How quickly will the disappointment be forgotten when 32 gig / quadcore / nvidia GPU's are released?
Apple's definitely playing the long game here. When the retinas came out, the absence of an ethernet port was a bit inconvenient for me, but now I don't miss it at all. It's possible that in a few years, when this model matures and goes down in price, the touch bar gets more wide support, and everything uses USB-C, then it will make a lot more sense to get one.
How hard could it really be to make a basic Linux desktop environment work sorta close enough to OS X to make enough people switch to finance further development? My quick and dirty estimate is that 50 good people could pull off a great first release in 18 months.
(I do have relevant consumer UX software design management experience and feel that I can do reasonable quick estimates based on that.)