He didn't say you can't use Linux or MacOS, he said there's still a culture of being Windows and Microsoft only across .NET shops. As an ex .NET dev I can confirm, the community is quite close minded, language is awesome.
Why do I care if other shops are Windows-only? The language and ecosystem are phenomenal and Linux support is first-class.
> As an ex .NET dev
Just curious.. what language(s) are you using now?
I think it's changing a lot recently. Our eng team of ~150 has been fully macos for several years now and we've deployed to Linux for ten.