The opposite is common knowledge: we
must have specialized hardware/software for language, otherwise we'd never be able to learn a language with the meager amount of information we can pick up in a year or two of occasional examples.
There are plenty of examples of clearly specialized hardware/software that nevertheless needs some fine-tuning and is not immediately available in newborn children. Newborns also can't digest solid foods, don't have teeth, aren't able to produce offspring, don't have breasts etc. And yet no one is arguing these systems, many of which will only be apparent months and years later, are not built in.
Even for other cognitive abilities: newborns have fully functioning retinas, yet are unable to see at all for a few days or weeks, and are unable to notice color for a good few months. However, the visual processing areas of the brain are virtually identical in all adults later: they are clearly part of our genetic makeup.
Also, you're confusing the ability to acquire language with general intelligence in your argument about geniuses. This argument is doing the opposite : it's saying that acquiring language is not some feat of intelligence, it is merely a specialized evolutionarily-acquired capacity that all humans share, just like visual and auditory and motor processing.