[gracenotes]

One of the most important things in "professional" writing, which includes technical writing, is clarity. Sticking to a style in that context is important because you shouldn't draw attention away from what you're saying to how you're saying it. The same thing is true of code style, where I think style guides really do improve productivity in codebases touched by multiple people.

As you mention, you could also see specific usage patterns as shows of "professionalism" (again in quotes... it's a word that I think should be used carefully re systemic biases). But it's perhaps a little reductionist to view informal contexts as not-caring-about-correctness at one end and professional contexts as caring, because there are many aspects of communication in both that are "incorrect" for different reasons. Usage patterns in work environments are not strictly more correct, then.

As the article proposes, being bothered by ungrammatical language is more often just an issue of sensitivity to stimuli. At least in conversations, those of us with the good sense to be descriptivists can hopefully tell when additional clarity would be helpful and when it's just putting other people down to try to look smart.