Have you drive a car? or have you ever repair/reinstall a software in a PC because it crash?
I both cases you really don't need to know nothing about hardware. In those days there are very specialized programming languages. If you wanna made drivers, antiviruses and embedded programming you will definitely need C. If you wanna made webdevelopment you will never need t0 know about C. you will need to know about html, css, javascript and tons of other web frameworks.
In short, If somebody want to cut a leaf of bread, doesn't need to know how it made the bread or the knife, but of course they need to know how to use it. :)