The funniest (and most sad) thing I recently saw at our local public library. They have rows of shiny new iMacs, you know the ones that taper to a thin aluminum edge (read in a Jony Ive English accent). These replace rows of what were just a few short years ago brand new Dell PCs, but which were regularly breaking down. However, attached to the shiny iMacs are a cheap keyboard and mouse since the aluminum ones might be too expensive, and each and every one was running Windows 7 since they had to connect to the library backend which probably runs on Windows Server. I know that Macs can natively run Windows through Bootcamp (emulation not necessary), but I don't get the idea of using iMacs; if they wanted Macs, they could have bought Mac mini models I think.
Anyways, I say use whatever you like and want, MacOS, Windows, iOS, Android, Linux, Chrome, etc..