I agree and also swear by Linux for "heavy lifting" and server operating systems. We extensively utilized the operating system at my former workplace for number crunching. Rock solid. I maintained racks and racks of Sun hardware running Red Hat linux. I also administered Linux-based mail servers between 2001 to mid-2005. Very reliable. One of my servers once went 3 years without a reboot.My son, a computer engineer for Norton Hospital group in Louisville, swears by Linux.
But for consumer use? Nope, Graphical User Interface (GUI) is simply not there yet. Hence Apple and Microsoft rule this space.