You've got [American] schools admitting people quite literally to graduate schools who only havea high-schooldiploma, because they misunderstood what the credentialrepresented.
But states considering switching say they'll put more emphasis on the equivalency credential or diploma they issue rather than the test taken to earn it.
MIT, along with other academic shrines, may do all this while preserving the value of what it really sells: spots in the lecture hall and dorm rooms, the chance to interact face-to-face with a prestigious faculty and like-minded students and, a golden credential, the MIT diploma.
One reason for the relatively large high school completion rate is that the United States offers a number of "second chances" for students to obtain a high school diploma, including attendance at special school-based programs and obtaining a General Education Credential (GED) credential, usually by passing a high school equivalency examination.