It's from a culture of people who cheat to get ahead, because they come from a society SO competitive, SO cutthroat, and SO obsessed with education & testing that cheating is encouraged and rewarded...because its rewarded in the workplace, in the broader economy (up to a point), and in the political body.

Of course, there's also the Chinese, who cheat because they are international students paying several multiples of the tuition and the university doesn't want to upset that gravy train in the wake of several federal funding cuts. Also because your rank-and-file Chinese students at most American colleges suck at speaking English so they, except in pure STEM, need to cheat in order to pass in the first place.

Problem is when the professors are being assessed on how the students do, instead of how honestly they assess their performance, there's a lot of disincentive to root out cheating. Universities have generally been marking their own homework on this front for a long time, and their morphing into a business which sells degrees has turned this conflict of interest into a real problem.