It is more than that though. Let's take a kid who has a good feel for math, but make them do several pages of addition and subtraction problems every night for homework instead of teaching them that there is such a thing as "math" and what they are doing is simply "arithmetic". Run this into the ground until they get sick of the subject.
Now finally introduce some math formulas, but don't tell them what they are learning -- instead they just have to memorize these expressions without purpose. And since this kid isn't really good at anything artistic (can't even begin to draw anything recognizable because they haven't ever been taught some basic techniques), how about we have them combine the math with an art project "to make it more fun", then fail them in math because their art is sub-par, and the results makes it "obvious that they didn't even try" (not that they don't know how to do art).
Is it really hard to take a simple to understand concept such as the area of a rectangle (that the kid already understands) -- then instead of telling them that the area of a triangle is "base times height divided by two", how about drawing a box on the board, and drawing a line from corner to corner making two triangles. Now it is obvious why you take the formula for a rectangle and then divide it by two to get the area of a triangle.
Ok, lets take this one step further -- you need to figure out how many feet of siding strips are needed to fill in the peak of where a wall joins a roof. "Hey I know this, it is base times height divided by two". But then you order the materials, and you come up short, because you have waste at the ends due to overhang (so you really need to draw out your triangle with the base several inches wider [add 2x the height of your siding strips to the base]). That is where the simple schooling didn't translate to the real world simply because the kids are taught to memorize answers for a test.
Now kids say, "I'd like to do the work necessary to get good grades, but I don't want to."