"It took Redmond until 2000 to create a usable server edition."
Sure, with AD it was far better for larger networks, and could compete with Netware.
Still, before it, your option for a server were expensive Unix licenses (and the hardware to run them), or Netware - just developing for Netware was more complex and you couldn't reuse your Windows skills, and there were less software available.
NT4 was OK if the network wasn't large. Just it made more sense with NT4 clients, Win9x wasn't really designed for networks.
OS/2 remained a small niche.