It is obvious that the teacher quoted in the article is not up-to-speed with the current status of Linux in the computing world. A majority of super computers use Linux, most of the web servers on the Internet use Linux, and the list goes on.
There are many reasons why Linux is a good operating system to learn but here is my take on the subject. Linux should be a mandatory learning experience for kids, especially kids interested in the IT industry as a career. Much like the learning the basic building blocks for an good education by learning the 2+2=4 and that i comes before e accept after c, learning Linux can provide a life long skill set to an aspiring child that will serve them well throughout their IT life.
When I first learned about Linux it was because my company was sending me to a class to learn UNIX. We were about to get some UNIX workstations and my boss wanted me to have a basic understanding of UNIX. When I got to the class the instructor told us that he would be using Linux, RedHat to be exact, to teach us the basics as at the CLI level almost everything was the same.
Once my class was over I was sent back out into the IT world with my new skill set in UNIX/Linux commands. Little did I know that the basic building blocks I learned in the Linux class would serve me so well in the years to come.
The first thing I noticed when I returned to work was that I had a new fascination with the CLI, even in Windows. Being a Windows users from a very early age I had been infused with the thinking that if it was not in the GUI then it did not exist. I soon learned that even in Windows there are some very powerful tools available only in the CLI and many of the tools were "borrowed" from the UNIX side of the house. When I started getting into networking and was asked to learn how to use Cisco products I was again amazed to find that my UNIX/Linux training paid off as the Cisco IOS is UNIX based and best done through the CLI. When I purchased my daughter a MacBook so she could make video and music projects I was pleased to find that my UNIX/Linux training paid off again as the Mac is UNIX based and the CLI uses most of the same commands. At home I run a mixed environment of Windows, OS X, and Linux and the ability to make all three operating systems work together makes me a more marketable IT person, in my humble opinion. I tell all people that I meet aspiring to enter the IT field to learn Linux, at least the basics, as it will serve them well.
I submit that instead of holding kids back, Linux opens up a whole new world of opportunity. Here is a theoretically example. Let's say that company X is hiring new IT employees and has a limited budget. Company X runs a mixed environment of Windows desktops for the majority of the employees, OS X for the marketing, A/V, and public affairs department, and a mixture of Linux and Windows in the server room. Actually sounds like a lot of real companies. Company X gets a bunch of resumes and starts to weed them out. Do you think Company X wants to hire a Windows only employee, an OS X only employee, and a Linux only employee or an employee that can do all three?