Yeah, not sure who the author is, but it feels a bit like a college student's PoV. I think C# got a popularity boost through it's inclusion in Unity - so if you're a hobbyist or a freshman, you very likely only know it the context of Unity.

Same with Objective-C, which is technically a general-purpose language from the C family, with a history that predates the iPhone by decades - but is nevertheless basically "the iOS app language" today.