That's the point. Professors at research institutions are NOT educators --- they are researchers. Their job is to lead a lab or group. If you look at the terms of their hiring at a university, it is not actually part of their job description to educate students. They have the responsibility to deliver lectures, perhaps one course per semester, and that's it. I'm not saying it's right --- I think it's wrong, but that's the way these schools work. If the school does actually emphasize teaching as one of its primary goals (which it often isn't), then we have a problem of the school not carrying out its directives through its faculty.
Second, about the hand holding; it'd be great if the school were willing to allocate resources to perform extensive teaching, but that's not what college is for. In the example you used, if people needed to review algebraic principles, what are they doing in a Calculus class? That's what I mean by the failure of America's primary/secondary education. I know that makes me sound elitist, but the simple truth is that primary and secondary education needs to vastly improve. A high school graduate should have all the necessary tools and skills to transition successfully into undergraduate level courses, but often that is not the case.