Why?....You have been to China right? ...lol
...Because, foreigners are golden cows for Chinese schools.
To ensure you have the right papers and assiting you to get the right visa, is the law. Or at least, to not accept you, enrolling with the wrong visa, is!
And the law, even here, should mean something, shouldn't it? At least sometimes....
It is common practice of schools to have some leverage over new students coming to China. Whom, regarding to your advise, should trust school administrators completely. Sounds very gullible.
They can make up all kinds of reasons, for you to get papers, documents, copies of this and copies of that for totally inflated prices and fees. And if you disagree or question them, they can kick you out or threaten you.
Happens all the time, at least in Beijing.
Plus, why wouldn't they give him or her the papers, he needs to enroll for his course? Doesn't make sense to me. Plus it is literally illegal to study on anything but a student-visa. For a state-owned University, and for people, as you put it, 'knowing hat they are doing', they should know what the law requires. And thus here my verdict: unprofessional, probably skimming potential students, inefficient.