I wrote a longish post criticising Farnam Street's (and others) called the mental model fallacy.[1]
My key beef is this: I think the vast majority of people who write about mental models are making a mistake in their reasoning: yes, successful practitioners succeed in part due to their mental models. But no, you can't learn their mental models from reading.
My belief is coloured by experience: while I was reading FS, I was building up a small company in Singapore, eventually hitting $4.5 million in revenue with a team of 30 by the end of three years (I managed the engineering side of things). I was struck by how little FS touched on the mental models I had to learn, and what I found useful. And then I realised that the mental models I had were really, really difficult to articulate.
I've since concluded three things:
1. The mental models that matter are tacit in nature (as opposed to explicit). You can't communicate tacit knowledge, in the same way that you can't describe how to ride a bike — you just know. I think that successful practitioners have superior tacit mental models. A good software engineer, for instance, may try to communicate what good code looks like, and what the principles of software design are, but in practice they just feel disgust when they look at bad code, and feel awe, or happiness, when they see beautiful abstractions. https://en.wikipedia.org/wiki/Tacit_knowledge
2. Humans learn by constructing knowledge from what they already know. (See: Seymour Papert). This implies that if you are not a practitioner, you cannot possibly communicate tacit knowledge, because you do not have a base of experience to build on.
3. Written mental models are useful only as guard-rails for practice. This is why Ray Dalio's Principles was so intriguing to me — here was a top level practitioner taking the time in his retirement to codify his tacit knowledge. That's incredibly rare. And it's still really hard to use — tacit knowledge is by definition extremely difficult to codify.
Like many here, I found FS's writing to be amazing when I first subscribed three years ago. It's gone rapidly downhill since; for a long time I thought I was the only one to think that. I'm slightly encouraged to see that I'm not the only one who thinks so.
I get it, the guy has to feed his family. But I do pine for the original FS, where he went deep into a few topics and worked out the secondary or tertiary implications of each mental model he describes.
[1] https://commoncog.com/blog/the-mental-model-fallacy/