LMAO, like the richest man in the world who provides the operating system for ~90% of the workstations and ~70% of the servers shipping these days needs advice from linux hacker "noobie". Sure, he could abandon those users, like Apple and Red Hat have done to their users, but that's when you lose them. I was an Apple devotee at one time (even sold them part time at MicroAge), but when they left me and my 3 Apple II's behind they lost me not only as a vendor of their products, but as a regular customer, along with thousands of others. Good thing I didn't ever switch to NeXT or OS/2 either, as those customers got shafted in the end as well. My advice to you, stick with your hundreds of incompatible versions of linux, and leave windows and its users needs to MS.
How did apple abandon its users you could run OS9 Applications for years after they made the move to X.
Apple didn't abandon, they provided an upgrade path.
First, they included "Classic" running within OS X for OS 9 applications. This environment sometimes ran OS 9 programs even faster than booting straight into OS 9 on the same hardware.
Second, they provided dual-booting into OS 9 and OS X for those rare programs that just wouldn't run under Classic.
Third, a couple years prior to OS X, Apple released an API that contained about 95% of the system calls normally used in OS 9 applications, requiring little modification to most programs to this API. OS 9 programs conforming to this Carbon API could run on OS X natively.
Fourth, for the transition to Intel, Apple built in a seamless emulator for PPC applications. You don't even know it's running unless you check. For those people using XCode, compiling your program to a universal binary (PPC and Intel) is simply a checkbox.
I wouldn't call that abandoning users.