And yet, Apple grew the number of Mac users from 60 millions in 2012 to 100 million users in 2018. In fact, more than 50% of those who buy a Mac has never owned a Mac before.
Seriously! Support these numbers, please. Also, that has to be active computers, in percentage and not just a cumulative number. Windows can pull much larger numbers out of the air, too!
Support for the OS system comes from the institutions - basically, it means the OS supported will be the majority, by a huge margin, not 60-40 or so.
Apple had ~95% market-share of the computers in colleges in the early 90's - it is the inverse now. A similar thing happened with the iPads vs Chrome Books. Institutions support for Apple has crashed; and Chrome Book is winning from the KG level up!
The sad part of this whole thing is that it takes minimum effort from Apple to keep their Mac lines in the more popular - all ports as in '15 MacBook Pro/Air as a simultaneous line to satisfy us "convenience crowd", while giving the "real pros" all fully enabled USB-C ports only in their "professional" models. They just needed to keep the 2012-2015 MacBook Pro/Air modules alive.
It is cheaper to make motherboards and chassis with just identical USB-C ports, instead of all those other ports popular with people; so, charge the peasants a bit less for these "non-professional" models, so that the Pros can feel better about their "superior" Macs. /s
IRL, charge the well ported models (including MagSafe) a couple of hundred bucks more and see if they sell. Almost like a costlier SE model of the each of the Mac computers! Also, stop soldering the traditionally added components, anything outside the SoC.