Actually, most schools are moving towards Standards based grading, at least in the K-5 grades. Middle Schools are starting to adopt it as well. It is fairly difficult to move away from the accepted letter grade systems, but it has been slowly happening over the last decade.
Standards based grading means you are graded on a number scale, depending on what your mastery of the subject is. It is also a lot harder to assess than traditional percentage based grades. So it eliminates the importance of busy work.
Obviously it is a much better indicator of skill, but there are some large flaws here. Say you have a PE class, and a student in that class never dresses out and never participates, except on the few assessment days. The student runs a fast mile or does a bunch of pull ups, but is only participating on about 5% of the year. With a standards based system, they would receive high marks in the class. But is this really a good preparation for the real world? I consider myself a successful person, and I will tell you that my success has a lot more to do with my work ethic than my skills. Will this student try to tell his boss that he only needs to come in one day a week because he can fulfill his job requirements in that time? I'm sure there are a couple jobs out there where that will fly, but not many.
As for your other complaints, it sounds like you have a problem with parents more than the schools. And I'm right there with you, schools are a product of the parent community. There are good and bad teachers on every campus in the US. The deciding factor in the quality of the education will always be the parent.