The word "advanced" is relative to the intended audience and it's obvious how he meant that word to be applied. The author wrote:
", chances are if you are considering studying advanced mathematics you will already have formal qualifications in the basics, particularly the mathematics learnt in junior and senior highschool (GCSE and A-Level for those of us in the UK!). "
The author is not a Fields Medalist writing to other PhD mathematics graduate students. In such a case, the adjective "advanced" would have a different meaning.
Sure, I'll buy that in principle. But wouldn't you agree that it mostly matters if someone is recommending some shady financial product or otherwise high-ticket item? What's the worse that could happen when someone makes (text)book recommendations?
Affiliate links are also a good way to compensate people for curating valuable information. So the sort of "it goes without saying affiliate links are bad" attitude is kind of a mystery to me.
A year or so ago a chum asked me to take a look at a paper that some of her quants were basing their work on. When I dug through it and pulled out all the plagiarism in it (and I do mean that; it had literally been hacked together out of other papers by some chancer in a middle-eastern university) it turned out to be a Crank–Nicolson method, and then when I saw what they were doing with it, I reckoned they could have just used a crayon and drawn over the graph they were interested in to get their smoothed graph. I do know that soon after that she got a job somewhere else. You can find hacks and chancers in every walk of life.
[1] In the above text, "hack" and "hacker" is used in the pejorative sense, similar to a "hack journalist".
