Depends on context/audience.
Much of web writing (Twitter, texting etc.) lends itself to "abbreviated" more informal language. As do some forums. Although, I notice that most posts here are more serious about writing well, some more "casual" expressions sometimes thrown in. Guess that is because we are all pretty serious readers, lol.
On the other hand, I don't want to see an article in a major newspaper written in "Newspeak." Or a technical manual. Or a novel. Part of what makes a good "literary" novel good is its use of decent grammar/sentence construction. The prose can "sing" sometimes.
Nor would I want to read a serious non-fiction work, say a history, in "Newspeak."
Is "Newspeak" the new term for more casual writing? To me that term reminds me of "Newspeak" in Orwell;s 1984. Not a positive association ......
Perhaps I am showing my age.
Not that "vernacular" writing does not have its place. For example, I am thinking of some of Scots or US Southern writing. But the terms used are generally long-standing, accepted terms. But it seems to me as if it is meant to evoke a sense of time/place. That can add to the richness.
I think being able to write well from a grammatical and spelling standpoint is good discipline for our brains.
I could go on, bt i wll stp.
Another good post, Justin Nemo. Thanks.