I don't know.
But if I may, I would like to venture a guess.
Unfortunately, today we are neck-deep into a system where a student's worth is defined by the grades he gets and not by how much he learns. This is dangerous, but what is even more dangerous is that the system succeeds in convincing the students that their worth is in fact defined by their grades.
Our worth means everything to us. It sits at the very core of our identity. The last thing that we want to be is worthless. What happens when something is worthless? It becomes dispensable; you can throw it in a garbage can and no one will look twice.
Hence, we can understand why we see students resorting to unhealthy pill-popping, hair-pulling, pillow-screaming, midnight-oil-burning habits in order to get the grades that they want.
Correction: in order to get the grades that the system wants them to want.
If we push a student hard enough, long enough, and consistent enough, pretty soon we'll see that he will entertain the possibility of getting the results he wanted by any means necessary. It doesn't matter how he gets the A, as long as he gets it.
I'm not saying cheating is okay, I'm just saying I can understand why students do it. We, as a community, have, consciously and unconsciously, "educate" students to take the grades as priority over learning. I am saying this with such confidence because I was such a student, and many others have walked in those painful shoes.
What happens when the result is being put more emphasis than the effort? One thing will happen: the effort will become secondary. The effort becomes less important than the the result. As long as I get the result, I am happy - regardless of how I get there.
What happens to the oft-repeated saying, "The means don't justify the ends"? It seems like a lot of students don't care about the means anymore - they are going straight for the ends.
Can we blame them? When the "You have to get straight As and nothing else!" slogan is being pumped into their brains day in and day out, it's not a surprise that you get students who find cunning ways to get the straight As that we have efficiently and effectively advertised to them.
We, consciously and unconsciously, created the environment whereby students lie and cheat. As a result, we produce A+ students on paper with F- mindset in real life. We directly and indirectly produce people who don't care about the effort, as long as they get the results.
Don't be surprised then when we have construction workers who cut corners, lawyers who cheat to win, teachers who just want to finish the syllabus, scientists who fake the experiment results, supervisors who water down students' PhD theses, and so on.
It's not rocket science - what you give, you get back.