A couple other answered but I feel life I owe it to you.
First of all, I don't recall making any particularly bold claims other than that I find culture and language fascinating. I specifically avoided making any claims, instead pointing out his works so that anons could form their own conclusions.
It didn't. I suspect language is just part of who we are as humans, another z-factor that sets us apart from lower animals.
A gesture, a grunt, between people of the same culture, just about anything can be language. It has a shared foundation of experience that gives it meaning. From his perspective, culture(in whatever small way) came first.
Wittgenstein wasn't as interested in culture as the structure of language, but he demonstrates that it was on his mind, in terms like language-game and world-picture.
prawfsblawg.blogs.com/files/wittgenstein-on-certainty.pdf
To bring it back to this particular topic, for one thing Wittgenstein absolutely shits on the sort of ultra-prescriptive language theories like the thing in OP's image.
On Certainty is also quite good for understanding how to deal with [people] like Marxists for whom there is never sufficient evidence, proof, or logical argument to dislodge their beliefs. I wouldn't say it is required Holla Forums reading, but a quote here and there could be golden.
To add a bit of personal editorial: It also means that we are winning the culture war. That might not necessarily mean what you think. We are poison to them. Our hated right-wing nationalist patriarchal what-have-you culture is their direct antidote that must be kept from the borders at any cost. They must police WORDS AND MEANING ITSELF to prevent our infiltration. (Not to mention history, tradition, religion, et cetera.) It is why they needed Academia on their side.
If the Jews and Marxists DO win this culture war, it will only be because they will have disposed of and replaced culture as we know it.
Will we allow it? Fight on, brothers.
No apologies for wall of text or soapbox tone.