Denial? Dude, almost all of the world's servers that aren't using Windows Server (not many use Windows Server, but it is worthy of mentioning. Its market share is in a nosedive) are running some variety of a GNU/Linux operating system. You can run basically anything on GNU/Linux one way or another too, from Photoshop (not natively, but that's barely noticeable) to video games. It's only getting better. Windows's days of relevance are numbered since Microsoft has started going heavy on the Linux stuff (subsystem for Linux, .NET Linux compatibility, etc). Apple is slowly phasing its server out of existence, not to mention that everything you can do on Mac you can do on Linux except iOS development, since Darwin is in no small part a bunch of stuff ripped from BSD and friends. The only people left without much native stuff on Linux-based OSes are hardcore gamers and creative types, but that gap isn't really one worth filling right now since so few of those people use (let alone know about the existence of, with few exceptions) Linux-based operating systems. You could definitely run an enterprise on Linux alone. Microsoft and Apple not required (unless you want an iOS app).

>learn linux and live with the pain of not having enterprise-grade software on your platform You're kidding, right?

Censorship, surveillance, war on armaments (from firearms to encryption. Yes, encryption is a weapon. See: the US govt's freakout when PGP was published online), and authoritarianism.

I sure do trust this! /s