I think most are just ignorant of what .NET is today vs 10-15 years ago. From my own personal findings, most on HN and general online dev space think it's Windows only and that hasn't been true for ~8 years or so. Microsoft has shifted to an open source approach for almost everything and Linux & Mac are first class citizens.
Pretty much every non-GUI (and GUI if it's Avalonia/Uno/etc.) .NET application, unless it uses niche things like windows registery or management API, is by definition platform agnostic and runs wherever .NET runs (macOS, Linux, FreeBSD(with caveats), Android, iOS, Windows, sometimes in browser with WASM). Most businesses which have moved away from old versions run their server workloads on Linux hosts within K8S or otherwise.