As a C# zealot, I would have a hard time providing an unbiased take, but its probably the "whole picture" ideal that makes developers take to it so strongly. When working with C# (aka some specific flavor of .NET), you are embraced with the following:

  - Visual Studio, probably the best IDE ever created.
  - With .NET (Core 3.1~6), code that usually "just works" x-platform.
  - Mostly-workable application development ecosystem as of .NET 5. 
  - Ecosystem of first-class CI/CD/Cloud/et. al. products & features.
  - World-class debugging experience, even across the network.
  - Stable versioning scheme with dependable LTS options.
  - Confidently run mission-critical loads on latest Windows Server platforms.
  - Very large library of high quality 3rd party dependencies (nugets).
  - Trivial to configure own nuget server for internal/private use.
  - Virtually everything you need is a first class dependency.
  - LINQ
  - Very good GC, especially when configured and used correctly.
  - Strongly-typed with very expressive language features as of C#8.
  - Fast compilation times, even on monster projects.
  - Principally maintained by largest software company on earth
  - Maintained by the open source community as well
  - Extreme performance (.NET Core optimizations, Kestrel, Disruptor, et. al.)
  - Extreme productivity (VS tooling, Self-Contained Deployments, Blazor, etc.)