Hmmm in hindsight you're probably right. Though he does refer to libraries using abstract algebra as having "meaningless terms," which doesn't really sound like a positive opinion about the subject. It's important to have the correct terms, and watering them down just creates ambiguity. If software abstractions stem directly from math, there's no reason to hide the fact. But, like you said, it seems like his point is that using abstract math in libraries raises the barrier of entry for new developers and that they shouldn't need to learn abstract math to be able to be productive, not that he personally dislikes the topic.

It's definitely is possible to go overboard with operators, making a codebase very confusing. Case in point: the lens library. Though those are optional, and the best practice is to just use the actual word functions.