If you want to get your word out and communicate, you can do that as long as you can type. Having someone to fix your computer for you so that you can blog isn't illiteracy, nor learning to sign up to Gmail isn't comparable to learning to read and write. Or something else like that: the author was rather vague as for the technical skills he deemed to be required for literate modern life. But HTML "coding" sure as hell isn't one of them!
Being a geek and being literate in "geek" language and thinking is a different thing from living a life. You might as well say that because cars are so ubiquitous and in countries with certain infrastructure they're almost mandatory, people need to know how they work and to fix them in order to be "literate", so that they can drive out and communicate with people instead of relying on more knowledgeable people to fix them for them.