It is easy to see why the maths gets skipped. It is harder to teach, harder to sell, and a polished tutorial that imports a model and gets 95% accuracy in ten minutes feels like progress. So most courses hand you the library calls and move on. You can follow along, you can finish, and you can build something that runs. The problem only shows up later - when something breaks, and nothing in the tutorial prepared you to fix it.
That moment always comes. A loss curve flattens and will not move. A model scores beautifully in training and falls apart on real data. A class imbalance quietly wrecks your accuracy. An AI assistant hands you confident code that trains the wrong objective. The people who understand the maths know where to look: the gradient is vanishing, the learning rate is wrong, the loss does not match the goal, the data is leaking. The people who only know the library calls stall, guess, and copy answers that may or may not apply.
This is the difference between someone who can run a model and someone who can be trusted with one. Depth is what lets you debug a training run, tune it deliberately instead of by superstition, read a research paper and use its idea, and judge whether an output should be trusted at all. That is also why we built a wider case for going deep at real coding classes - because shortcuts feel faster right up to the point where they cost you everything you were trying to save.