The US military is as big on diversity as every other US institution now. They want more women, LGBT and non-whites higher up in the ranks, holding prestigious commands and in prestigious MOS fields.

The credentialism is downstream from the warped American worship of higher education. Traditionally only officers needed a degree, but now a degree and even postgraduate degrees are expected if you want to climb the NCO ranks and make it a career.

Rejected why?

They never finished high school. They'd be considered "uneducated" grugs. Not only that, but Basilone and many guys who served in WWII got up to all sorts of fucking around on liberty like fighting with and stealing shit from the MPs and officers, etc. That's less tolerated these days.

I get that it's a bad idea to recruit irredeemable pieces of shit, but the military has historically been a place where a young man would get a second chance to be a good citizen. The famous former US Marine actor (the strict drill instructor in Full Metal Jacket) R. Lee Ermey used to be a serial criminal before a judge gave him a choice between jail and the service. Nowadays they're more interested in a minority XYZ studies graduate.