I had to fight IBM, DEC, SDS, and so many other computer companies all my professional life (1956-1995) to provide computing my colleagues and I could count on. I switched to an iMac on retirement, in the hope that I could relax and enjoy a tool that worked for my photography, music and internet.
Sadly, that hope has been unravelling in the past few years. The newest versions of OSX refuse to accept formats that it supported in the past, and that are still in use by many people, including me.
Photography: I had a colour calibrator that worked on the iMac screen and on my colour printer output. Its software requires PowerPC support, which OSX supported when I bought the system, but which has now vanished. That's a real loss to me; new ones cost a lot, work in different ways that I'd have to sort out, and only work only with printers newer than the one I have.
Music: I spent over a decade recording music in MIDI format before MPA was available. (I'm only the 2nd person in history to have succeeded in publishing recordings of all the harpsichord sonatas of Domenico Scarlatti, and that's how I managed to do it.) OSX no longer supports MIDI.
It also no longer supports MPA, the audio-only format adopted by many magnificent musicians, some of whom sent me their recordings in thanks for mine, and which to me are unreplaceable. And, as a coup de grace, when I tried updating to Sierra (9 hours downloading with DSL) in hopes that some of the problems might be resolved, I found that all audio was coming solely to my left earphone and that there was no way to fix that. I had to haul out Time Machine and revert back to Yosemite (3 hours more with my computer dead) to get my sound back.
I thank Apple support staff for trying to help, but they sadly admit that OSX has indeed now killed its past in all the cases above.
Meanwhile a 2005 Windows XP system (I run it offline) supports a 1980's DOS BASIC compiler, a 1990 Win3 Sigmaplot, a 1996 NT WordPerfect, a 2011 data acquisition system... as long as I'm prepared to put up with the techie details that always seem to pop up every time I want to try anything new, just as they did in the old days.
Apple used to make systems that plugged in and worked for real users, not just technobabble junkies. (That's Linux territory.) Of course computers need to keep up with the new, but I pray that Apple might still return to its real user base, people who value a system that works for them flawlessly, without hassles.
To begin that return, never ever withdraw support for what you achieved in the past.
other notes on computing