People are taught to fear math just like they are taught to dislike vegetables. If you can add, subtract, multiply and divide, math is easy until you get to weird things like proofs.
Your point “teachers’ inability to communicate lessons” was right on. In a teaching class in college, I was required to explain how to solve an algebraic equation. Afterward, a girl comes up and says: “I took algebra in high school — got good grades. Here, I took college algebra — got good grades. This is the first time that I understood what was going on.”
In my work life writing computer software, I always converted everything into the language and concepts of the audience, be it managers, users or colleagues. For high school, I would probably convert everything to money and cooking.