Sorry, there was an implied premise that I probably should have included.

These US schools are teaching classes only in English, so the students' inability to speak, write, and (in some cases) read English means that they can't do the work.

I've observed them brazenly cheating during tests by looking at other students' papers, but I think it's more common to hire English speakers who know Chinese to do the work for them. They fail some tests, sure, but they end up with C's overall and a diploma to take home.

I actually had a classmate in college who ended up founding a successful business that exclusive connects American speakers of Chinese with wealthy students from China to write their essays and do their homework.

Because examinations they're passing and all the classes they're not attending are conducted entirely in English only. What I've observed happening in some places is that some specific schools are predominantly populated by rich international students from China and they pay someone else to attend classes and take their exams, or otherwise behave in cheating behavior to get the grade, but they themselves are not attending class or learning anything useful.

It's a scam on both sides and it devalues the degrees.