Microsoft drank early OOP koolaid and thus powershell suffered from problems that were well covered by the time etc…

Ray Norda being pushed out after WordPerfect bought Novell with their own money and leveraged local religious politics in addition to typical corporate politics killed it.

Intel convinced major UNIX companies to drop their CPUs for IA-64 which was never delivered, mainly because the core decision was incompatible with the fundamental limitations of computation etc…

The rise of Linux, VMs and ultimately the cloud all depended on the CLI.

Add in Microsoft anticompetitive behavior plus everything else and you ended up with a dominant GUI os provider with a CLI that most developers found challenging to use.

I worked at some of the larger companies with large windows server installations and everyone of them installed Cygwin to gain access to tools that allowed for maintainable configuration management tools.

There are situations like WordPerfect which had GUI offerings be delayed due to the same problem that still plague big projects today, but by the time the web appeared Microsoft had used both brilliant and extremely unethical practices to gain market dominance.

The rise of technology that helped with graphics like vesa local bus and GPUs in the PC space that finally killed the remaining workstation vendors was actually concurrent with the rise of the web.

Even with that major companies like SGI mainly failed because they dedicated so many resources to low end offerings that they lost their competitiveness on the high end, especially as they fell into Intels trap with Itanium too.

But even that is complicated way beyond what I mentioned above.