IMHO a truly accelerated program would see Calculus done in the 10th grade, with Diff-EQ+Multiavariate Calculus/Real Analysis in the 11th and Linear Algebra/Abstract Algebra in the 12th.
I tend to agree with you. A gifted math student has wasted a lot of time if they only find themselves in Calc I or Calc II by high school graduation. I think a good, compacted math curriculum would teach pre-algebra and algebra in 1 year. The next year would cover geometry and trigonometry. Followed by algebra II and pre-calculus in one year. This puts the student in calculus in 10th grade assuming they covered algebra in 7th grade. If they do a B/C curriculum, they're ready for Calc 3, linear algebra, or diff-eq as a Junior. A properly motivated, gifted math student may even want to take more than 1 math course a semester, and why not accommodate them? As I recall, Calc III, differential equations, linear algebra, and probability/statistics are not prerequisites for each other.
