Even neglecting his severe psychological problems, Wittgenstein was proved wrong on this particular quote. There is no way to describe arithmetics clearly and coherently (ty Godel), yet it still is one of the most useful tools that exist.
There are many things the usual languages cannot decribe clearly, and the clear definition of a language that can describe those things clearly is not possible.
Wrong! Language is a tool that can help us get near the very truth. It never can be the vessel of truth, since it is human made and flawed. It is flawed because we can only make words for what we can imagine in our heads. Philosophy is the search for truth, so language is the wrong tool. (this pretty much sums up the Tractatus, in a retard-comprehensible way.
He's not proven wrong, it's just accepted that it is very usefull to DO use language to search for truth, even if it is flawed from the beginning. Better to find something close to the truth, then not search at all.
On topic: Bravo for strat being about battles again!