I don't think it's unreasonable to expect high school kids to take Algebra. Algebra is not that difficult, frankly. I do think the bar is set super low in math in the USA. My son is doing a beginning alegebra boook at home, and he just finished third grade.
I think the USA needs to really wake up in math and science. I'm sure other countries have their high schoolers take Algebra, and they can do it. OK, I don't think everyone needs to take Calclus, but Algebra???