In many schools today, math is taught as a "holistic" subject, where algebra, geometry, trigonometry are intermixed and taught as a "integrated" whole. In theory, this would let students appreciate that there are many ways to approach a problem and that the same theorem can be proven via many methods. In practice, all it ensures is that students have an insufficient background in three subjects rather than thorough knowledge in one.
Bruce Lee said, "I do not fear the man that has practiced 10,000 kicks once. I fear the man that has practiced one kick 10,000 times." What our schools are doing is teaching different "kicks" (mathematical skills) but without following it up with the necessary practice required for students to achieve mastery of those skills. What we end up with are kids that know of mathematical theorems and mathematical results without knowing the results themselves.