I think one of the major failures of education over the past few decades has been an overemphasis on instruction. Educational reformers have told teachers, school districts, legislators... anyone who would listen... that a student could become proficient at anything if they were "taught" it correctly.
Imagine a baseball team that avoided practice. An orchestra that never rehearsed. A military unit that never drilled. An officer who has been instructed in firearms but rarely fires one.
What are you good at? In most cases, it is the thing that you spent time practicing. Instruction is wonderful, but it doesn't tend to go very far without time spent on the instructed task.
However, an expectation of practice puts some of the ownership on the one being instructed... and that doesn't work for our consumer economy. No, the customer is always right. In a student as consumer environment, all responsibility is put on the instructor.
Teachers are leaving the classroom in droves. People always say we need to raise salaries to stop the hemorrhaging. It may help a little, but pay for teachers has ALWAYS been on the low side.
I think what really changed was that all responsibility for the child's education moved to the teacher. It used to be more of a partnership between home, teacher, and child, but now a child's success or lack thereof is resting with the teacher alone.
Joey practices. Jimmy does not. When Jimmy fails to advance, no one considers that perhaps it has something to do with his lack of time on task. In today's schools, the teacher is saddled with extra paperwork and data meetings to try to adjust instruction in such a way that will allow Jimmy to be as proficient as Joey... but never require that Jimmy actually do anything.
Or, maybe, Jimmy really is working at it... but he still can't achieve Joey's level of proficiency. He just isn't as gifted in this area as Joey. Again, in this scenario, the teacher is still evaluated as coming up short. According to the educational reformers, teachers should be able to move all students to equal ability... regardless of time on task or natural talent.
This is why so many teachers quit within the first 5 years now. Being responsible to do a good job teaching is one thing. Being responsible for every x-factor in a student's education is demoralizing.