The language is spoken. Writing is written.
Origin of the word from "tongue" notwithstanding, language is cerebral in nature and expressed in spoken, written, or signed forms. Just because one of the forms of expression existed earlier or is more widespread than the others doesn't mean that it is more genuinely "language."
“The thing that’s really concerned many of us is the inability of many students to think clearly. It’s reflected in their writing. Some of it’s just gibberish. It reads as if written by someone for whom English is a second language, with mixed-up phrases and ideas. You ask them what they mean, and they can’t tell you verbally, either.”
When contrasting written telling with spoken telling, he should have said, "...and they can't tell you orally, either" as in an oral versus a written response.
And everyone should read
Less than Words Can Say and
The Graves of Academe by
Richard Mitchell.