A danger of such a world and such a set of assumptions is a watering down of the expectations needed to get that diploma. If we start to think that one has no hope without one, we start to believe denying a diploma to somewhat is akin to a death sentence or terminal diagnosis (I'm being a bit melodramatic). Could the assumption that one is handicapped without a college diploma the root of professors having to lower standards, deans bowing to parents' pressure to revisit grades, or the creation of programs catering to those who want to cruise on through?
Unfortunately, that has happened, from my perspective, with the high school diploma. The lack of a college diploma might exclude one from job security and good pay, but the lack of a high school diploma might just render one unemployable in the first place. As a result, schools push kids through the system, watering down expectations, creating creative means to get to graduation, and putting enormous pressures on teachers, principals, and guidance counselors to not let the students fail. There has been little energy at putting the responsibility on kids to step up the efforts to earn the right to walk at graduation.
This is to be expected in an age where we want to curtail funding to education. (Ironically, when something is seen as a need, as high school education is, it loses its value. People don't like paying a lot for an entitlement.) We tell schools to do more with less, but then punish schools when students fail to make it to graduation. Ideally, schools would establish and fund the means for students who can't make it through on the first attempt. It would be wonderful if students who fail to earn a C or higher in a high school course could be assigned some sort of guided study program where they completed work or received tutoring until they were able to earn that C or higher. This is, in essence, what summer school once did.
Eventually that philosophy should be part of what colleges offer, too. We have heard of the tremendous burden student debt is for college graduates, and many kids are walking from campus owing more than they would pay for a couple of cars. But the nastiest burden of those debts weighs down the kids who couldn't earn that college diploma.
Timothy Noah offers something helpful in linking educational opportunity to equality. I hope we can determine a way to make earning a diploma an opportunity rather than a ticket to be punched.