The problem with the standardized tests, though, is that teachers should be allowed to adapt the curriculum to meet the needs of the student, and the teachers should be trusted to know what's important and what isn't, not some bureaucrat or politician who wrote the test. The tests aren't necessarily well-written to reflect what students actually need to know.
As for kids with no motiviation, yes this is a huge problem, and it all goes back to parents not being responsible and instilling these values at a young age.
The problem with some of the current tests is that politicians take a part in writing them.
For most classes it is not hard to write a standard test. We know what math is suspposed to be taught and what science is taught. Social Studies is pretty simple too.
English is probably the hardest. Grammar is easy enough to test, but reading comprehension and writing are a bit harder. Not impossible though.