Back in prehistoric times (1988) when buying a computer the first question was "what kind of computer" and that meant which operating system. But to most people these all seemed the same, even if the only people looking were tech enthusiasts. Maybe this reflects a bit of today's world. Look at all you needed to know in those terms! Also "Is computing better with a mouse?" PS: OS/2 had no software.

@HariSeldn Here's a chart with Amiga. See how Apple ][ dominated sales until 87.