The post said specifically that if you wanted to be a writing author, you should ignore marketing books and write something unique if you want to have success. And as a full time author I had opinions on that,
Basically it’s true you need to be following your passion and writing something you care about. But if you aren’t writing something people will read, you’re also not gonna sell a single copy. What you need to do is find where what people read and what people like intersect.
For example: my first ever book was gods having math fights. It was fun and weird and a passion project and it sold like ass. My second ever book series was me playing Factorio for like 100 hours in a single week and needing to justify the time spent to myself, but I was smarter and researched what genres would actually read “guy builds factory” and settled on LitRPG and it sold decently.
My third and fourth ever book series were “omg I love Pokémon” and “I am a scalie but closeted about it and also I’m having a gender crisis.” No one read them either. My fifth published book series I once again went back to research before I published and then found a way to fit my lifelong dinosaur special interest into the existing genres. It sold like hotcakes.
Then I over researched and tried to write something specifically to marker but the passion wasn’t there and it sold only meh.
The point is you have to find that middle ground if you wanna make money and support yourself. Mix your special interests and passions in with the genres you enjoy that sell. Don’t worry about being unique, focus on writing something you would read that other people would read as well.
Also I get the love for On Writing but it’s also full of bullshit advice that only works for some people and also every single author trying to sell you a course on how to sell books is full of billshit because if they knew how to sell books, they wouldn’t need to sell overpriced courses.