There hasn't been a new operating system for personal computers in a decade or more. Millions of twentysomething computer users have known no other operating system than Windows. To people who get their kicks from computers and software, the arrival of an advanced new operating system is a breathtaking time. Linux isn't just reliable. Toasters are reliable.
Grandparents are reliable.
Linux is in a different category. It's designed to keep running no matter what happens. It's engineered to sail on smoothly even if programs start to misbehave. If Program A crashes on a Linux computer, Program B is totally unaffected. And the operating system itself remains cool and calm.