On the next to the last point, an institution the reader has probably never heard of (Stratford University in Northern Virginia) issued a huge number (1,697) of 29-month OPT (Optional Practical Training) work permits under the provision for STEM (science, technology, engineering, and math) graduates in 2009-2013, more than the entire Ivy League put together (1,668).1
Despite its name, there is no training involved in the OPT program; once a tiny and sensible operation, it was expanded beyond reason by both the Bush II and Obama administrations. OPT currently not only provides work permits for up to three years (formerly 29 months), it also gives employers a 7.65 percent tax break for hiring alien workers rather than American ones at the same salary because there are no payroll taxes levied on the former as there are on the latter.
Creating the broader set of problems described above is a group of marginal institutions that used to be blessed by a lax accreditation agency, the Accrediting Council for Independent Colleges and Schools (ACICS), but lost that fig leaf when ACICS, after a long, formal inquiry, was de-recognized by the U.S. Department of Education (DoEd) in December 2016. This left some 55 institutions with well over 100 campuses in limbo, still largely able to issue the Form I-20 that aliens can use to apply for an F-1 (foreign student) visa, but with no U.S.-recognized accreditation and virtually all with one or (usually) more of the collection of eight black marks noted above.
https://cis.org/Report/Dregs-Higher-Education-Damage-Our-Immigration-System