I agree that it's inexcusable. However, I look at my kindergartener who is currently immersed in recognizing fractions and fraction theory (pies, sets of things, cut up balls) and I ask myself why we can't accelerate these skills. Since I believe math and physics are languages (albeit left brain languages) and language - vocabulary, syntax, ability - is built through practice why are we waiting to introduce math skills? We certainly don't do it with English language skills.
do it = wait
Because in public education, they are forbidden from going faster than some bureaucrat (read: democrat) imagines the slowest child can go. No child is left behind, because no child is permitted to run.
I don't know what they've done to math curriculum these days! My son is a 5th grader and is just now reducing fractions. Division wasn't taught until the end of 4th grade. It seems that they spent 1st-3rd exclusively on addition and subtraction.
But at the same time, it seems to me that instead of simply teaching addition, they are throwing all kinds of things into the mix. The kids get a little taste of algebra, measuring and word problems with each newly added concept. It sounds good, to have them exposed to these things, and yet I wonder if that is part of the problem? Are we throwing in all these fancy things and losing sight of the fact that they can't simply add all that well?