The trouble with that is that it'll clog the courts and encourage the lawyers.
The REAL problem is that an education is not really prized. Oh, everybody knows that more education = more $$$ in a vague sense, but in fact, especially in minority communities, education is seen as "acting white" and is shunned.
A kid should be responsible for his own education after a certain point, but if all your friends discourage you, are you gonna get new friends, or go along?
Yes but who am I gonna sue?
The real problem is that to master a twelfth-grade curriculum (a real one) you need an IQ of 95 or above, and if your IQ is 95-105 you will have to work like a dog for it.
Many, many present high school inmates have IQs under 95. Prior to the 1970s, they could leave. Now, they have to stay, with failure in their faces every damn day.
Some of them internalize and get depressed, but many, especially males, act out.
It is completely and totally irrational to mix the below-average students, except perhaps the top quartile of that group, with students who are going to graduate.
But that's our national "education" policy.