Shew, if I wrote like I talked to other people it would be an entertaining disaster. When you speak, you're speaking to your specific audience, which could be your boss, your toddler, your spouse, your friend of 25 years, your in-laws, your candor in giving a presentation, this list goes on.

I write how I think, and how I think is profoundly shaped by reading, listening, and absorbing.

Write how you talk seems almost arrogant. Writing is an expression of an idea, and how I speak vs. how I write are so vastly different it really does amuse me to chew on this.

I suppose TFA is mostly focused on academic writing [0] (article quote) but the vast, vast majority of people in this world today are not writing academically, they're posting here, or sending a text, or work emails. Good writing means you don't need to assume everyone is an expert or a non-expert. The first thought that comes to my mind here is "mansplaining".

[0] So the common advice to "write like you talk" can be underspecified. It's good to avoid pretentious and formulaic cliches that mask the absence of precise thought, and separately to avoid dense and impenetrable jargon that's hard for non-experts to understand.