I couldn't disagree more. It gets too hard when you're asking students to memorize arbitrary equations that make no sense to them. It gets too hard when you give them 30 problems that look identical and they do 3 or 4 and figure that's good enough because they know how to run numbers through the meat grinder of a formula.

I don't see how students can truly learn if they don't understand the formulas they're applying and their relevance to the real world.