[markkm]

Math textbooks include topics in physics and theoretical computer science all the time. How is ML any worse?

Besides, a lot of introductory math textbooks are thinly veiled introductions to subjects the authors think are important.

[scoobyyabbadoo]

The difference is k means has literally nothing to do with linear algebra. Might as well sneak in a chapter on finite state machines, or zebras, either would be just as relevant to linear algebra, which is to say that at a certain point the topics in a linear algebra course should be somehow related to linear algebra.