It was printed in 1994. Linux and BSD (either FreeBSD or 386BSD, I can't recall which) where around, but Open Source (TM) as we now know it wasn't. Other, proprietary Unix systems were still viable and in use (AIX, IRIX, SunOS/Solaris, HP-UX and SCO just to name a few). Running Unix was not cheap [1]. Most X servers were proprietary and cost money (I had some friends that sold X servers for a variety of OSes and video cards at the time). The criticisms at the time were, in my opinion, decent enough but not enough to stop to duopoly we have now with POSIX and Windows.

[1] In college, early 90s---I got to use IRIX on a machine that cost $30,000 in 1991. PCs caught up and past it pretty much by the mid-late 90s. Also, I did some consulting work at a bank which used SCO. They paid God knows how much for every conceivable package available for SCO. The base system? Pretty much just a shell and some commands in `/bin`. Compiler? Pay. Network? Pay. TCP/IP for said network? Pay.