macOS is very different than OS X. Oops.
I'm Chief Engineer of a Web dev shop that do a lot of Ruby and Elixir development; we're almost exclusively a Mac shop. In the last year, we've brought up Docker as a core piece of our technology stacks. We're not, as an organisation, progress-hostile; in fact, I've lost jobs, plural, before for being too far in the opposite direction.
Sierra is the first Mac OS upgrade *since Puma* (10.1; 2001) that the shop I worked for at the time hasn't been standardised on across the board within a fortnight of GM release. We don't anticipate moving to Sierra before what will probably be the 10.12.2 timeframe.
A small number of teething problems on a new release are unavoidable, but Sierra has been extreme in the number, severity, and breadth of problems reported through the channels I follow. The number of reports of Macs becoming partially or completely unusable after the update dwarfs anything I have seen before, probably collectively. Apple have had issues before; have had OS updates that just didn't seem worthwhile (we skipped Mavericks and went directly from Mountain Lion to Yosemite); and so on. Never in our experience, however, have Apple dropped the ball so spectacularly while clearly believing they had dropped a mic instead.
The market is ripe for true disruption. Many Mac shops are sticking with Apple but gnashing their teeth and looking about anxiously while doing so. Windows is almost mind-blowingly better than it was 5-10 years ago, but it still seems to lack the consistency and unobtrusiveness that have been traditional hallmarks of the Mac. No other OS besides OS X/macOS and Windows exists that has anything resembling the end-user-friendly interface, business-friendly licensing and support, and third-party application support of those two systems. (The Year of the Linux Desktop was circa 2003; it's gone off in a radically different, more successful direction since then.) Apple are focussed on their iOS platform (their current herd of cash cows) and simply haven't paid the same attention to Macs as in years past; witness the all-but-official demise of the Mac Pro and Mac mini.
There's nothing else out there for us, or for lots of other shops. Some say "Apple shouldn't take us (Mac users) for granted as much as they are now". Others say "Never ascribe to malice what can be adequately explained by incompetence"; Tim Cook and Jony Ive are brilliant in the supporting roles they held for years, but their unfettered leadership is proving a problem for the platform.
Where do we go?