In my opinion this is not true. Writing is a form of communicating ideas. Structuring and communicating ideas with others is really important, not just in written contexts, and it needs to be trained.
Maybe the way universities do it is not great, but writing in itself is important.
(And I am aware of the irony in failing to communicate when mentioning that studying writing is important to be good at communication.)
Maybe I should have also cited this part:
> writing as a proxy for what actually matters, which is thinking.
In my opinion, writing is important not (only) as a proxy for thinking, but as a direct form of communicating ideas. (Also applies to other forms of communication though.)
In my opinion this is not true. Writing is a form of communicating ideas. Structuring and communicating ideas with others is really important, not just in written contexts, and it needs to be trained.
Maybe the way universities do it is not great, but writing in itself is important.