Plus, Apple doesn't care about macOS. HFS has bitrotted away, the OS itself has taken backseat to mobile, and Apple doesn't know if it cares enough about its enterprise and power users to even release "point releases" of their products - how much engineering tech does it take to replace a Haswell CPU with a Broadwell with no fanfare or ado? Just do it and make it available?
HFS is already being replaced with APFS which is excellent feature-wise, and is available in Sierra for testing purposes. I expect at this time next year we'll be seeing them use it by default on new macOS and iOS devices.
Macs are still shipping with 10-year-old GNU utilities. LOL
Maybe if one day Windows goes 100% UNIX.
For me the only downside really is the extra reboot after an OS update every 2 months to update nvidia driver and repatch sound kext.