The Vista of DOS
There are interesting parallels between Windows Vista and DOS 4.0. Like Windows Vista, DOS 4.0 was highly unpopular for many reasons. Like Vista, DOS 4.0 was often considered less preferable than the previous version (DOS 3.3/Windows XP) until the successor version (DOS 5.0/Windows 7), not radically different, won the hearts and minds of the press and users.
As with Vista, the software compatibility issues were hammered out by vendors, and by the time the next version came out, everything just worked. Not so much because the new version magically solved all problems, but rather because incompatibilities had been quietly fixed while the world wasn’t paying attention.
And much like with Windows 7, the resource requirements of DOS 5.0 seemed modest in 1991, while similar requirements of DOS 4.0 had been deemed outrageous in 1988. High memory support in DOS 5.0 relieved much of the conventional memory pressure, but it also required at least a 286. By the time DOS 5.0 was released, the the typical system was in fact a 286 or better, but that had not been the case when DOS 4.0 was released.