My idea on how to fix High School math. Spend the first 3 years doing nothing but mastering basic algebra.
I've seen from tutoring my siblings that basic algebra skills are what they lack. They concepts of trig and calculus aren't that difficult, it's the algebra that trips them up.
Leave the higher level math, for everyone but the most advanced students, to college. If I was a college math professor I'd rather teach a group of kids who have mastered algebra, than ones who've had a whirlwind tour of everything.
This might work for some people, but as someone relatively smart and good at math, this would just make me want to cry myself to sleep at night. A smart student can master algebra/algebra 2 curriculum in a couple of months. A problem with a lot of high achievers is that they already feel like they are wasting time in high school, this just aggravates that problem.
My suggestion:
Not everyone needs to learn that much math. Classes up to algebra 2 and also an intro to statistics are probably enough for most people. Note that this can be in high school or college.
However, for those who want to be mathematicians/scientists/engineers/technical people, math education should diverge probably around 7th grade. Rather than teaching pre-algebra or algebra or whatever they do now, they should start teaching the students how to do proofs. The best thing about Ma 1a at Caltech (http://www.math.caltech.edu/~2011-12/1term/ma001a1/) is that about 60% of the material could be taught to a smart motivated 7th grader. Making the students do proofs with help everyone figure out either that they love math and its beautiful or that they aren't really that interested in math. With a more rigorous understanding of basic math, learning applications like calculus is a lot easier.
I've seen from tutoring my siblings that basic algebra skills are what they lack. They concepts of trig and calculus aren't that difficult, it's the algebra that trips them up.
Leave the higher level math, for everyone but the most advanced students, to college. If I was a college math professor I'd rather teach a group of kids who have mastered algebra, than ones who've had a whirlwind tour of everything.