I am not suggesting NT is dead on servers at all. I am positing it would be dead had it not been for owning the majority of desktops. Those use cases are primarily driven as an ancillary service to Windows desktop[1], and where they have wider applicability, like .NET and SQL Server, have been progressively unleashed from Windows. The realm of standalone server products were bulldozed by Linux; NT wouldn't have stood a chance either.

[1]: In fact, Active Directory was specifically targeted by EU antitrust lawsuit against Microsoft.