Apple and other makers are screwing themselves up by obsolescing older software. I need access to my data. The applications that access my data won't run on the newer hardware on the newer operating systems. The result is I don't upgrade my hardware - I just keep making do with old hardware. I buy used computers for our businesses and family needs. I know of other people in the same boat. If the new hardware and OS can't let us use our older applications then we don't buy new. Apple and other vendors of hardware and OSs loses a lot of sales that way. They make nothing when we buy used.
Emulation is not that hard.
Keeping operating systems compatible so old software runs to give us access to our data isn't that hard.
We need backwards compatibility to move into the future.