- In May 1990, Windows 3.0 running on a Intel 80386 could run multiple DOS VMs simultaneously
- In April 1992, OS/2 2.0 finally supported multiple DOS VMs. OS/2 1.x supported running only one DOS app at a time.
While MS Excel had been available on Windows for many years before Win3.0, Word for Windows had only been released a year before Win3.0.
So many PC users would still have been using the DOS version of WordPerfect (and maybe the DOS version of Lotus 123). Windows 3.0 allowed the user to run many of their DOS apps at the same time, which DOS and OS/2 couldn't do.
Windows/386 could do that in 1987, but not many people bought it. Power users had DESQview/386 or something similar.
If IBM had listened to Microsoft, OS/2 1.0 could have done that in 1987 too... and then I think OS/2 could have been a hit and Windows 3.0 might never have happened.
So many PC users would still have been using the DOS version of WordPerfect (and maybe the DOS version of Lotus 123). Windows 3.0 allowed the user to run many of their DOS apps at the same time, which DOS and OS/2 couldn't do.