I believe the solution to the poor state of math education in the US is to give students a killer app for math -- namely programming.
If their math classes can facilitate building some cool games say, then maybe students would care more -- even if they find math difficult.
Math education could certainly use more fun, and I think most teachers who love the subject and are skilled (if not talented) mathematicians are capable of making it more fun and relevant. BUT most school districts have neither desire nor interest in looking for that sort of teacher ... and certainly not in paying them more. (So they get what they'll pay for.)
One reason for that situation: the majority of students won't respond to great teaching either... for a long list of reasons, one of which is that it doesn't start early enough (e.g. before sex). Another reason is that in most schools, education is not the first priority.
Who will develop this 'cool' curriculum? Teachers haven't got time. It's up to cool programmers to do that. So far, they haven't shown much interest. So the kids get left-overs.