The biggest issue is the graduation rate. Many of these for-profit colleges graduate students in the single digits: that is, only 9% or fewer graduate with a BA degree after 5 years. It isn't much better at a lot of the not for profits. The college where I taught had a rate of 15%, but there were a lot who returned after several years and completed their degrees. Once the for-profits have gleaned all the loan money they can, they do not accept returning students. The actual tuition rates are huge, and no one in their right mind would spend that much of their own money for a degree from a nondescript for profit college.
Typically, a huge percentage of the Freshman class dropped out after one or two semesters. A majority of the graduates were students who had started out at public colleges and dropped out earlier.
Testing for competency is up to the school. The for profits do most of their testing online, which means that the student usually takes the test unsupervised (and can get someone else to take the exams for them) and can retake the test as often as it takes to pass. Naturally, the tests are of the so-called "objective: sort, which means true false and multiple choice. The professors are paid very poorly,and have LOTS of students, so they only give this sort of exam, which can be scored in seconds. The ability to show competence in a language, as a critical thinker, as an accountant or practically any subject is limited with such tests.
There are LOTS of students who are interested only in passing the course. Many have zero interest in actually learning a useful skill, so long as the pass the course.
They often refused to buy the book, even when I showed them how to buy it online for a fraction of the bookstore price. Learning a language is basically learning the words and how to use them in speech and in writing. If you do not have a list of the words (which are in the textbook) it makes learning those words quite difficult.
Most of the for-profits should be shut down, as they serve only to put their students in debt for a lifetime. Other colleges should be regulated in such a way as to enroll more motivated students and to assure that graduates actually know something about their chosen fields. There needs to be a cost-benefit analysis to improve the results of studying for a career.