Being about "how not to use math" and about math as such are pretty different things. It's like you were teaching a class on car repair and assigning a book on consumer fraud.
No. It's like you were teaching a class on car repair and telling your students how to not screw up. e.g. "Do not ever adjust the stabilizer based on popular arguments such as ___ and ___ because it will only screw with the engine and may even cause permanent damage." It's actually very relevant, especially in the early stages of learning.
A transistor protected by a fast-acting fuse will protect the fuse by blowing first.