In any given year across China, the number of graduating students is something less than 10 million. (I tried looking up stats - couldn't find anything too helpful.) So, there's a lot of them, but there're a lot more people outside this system. Even if their demeanor didn't give them away, number alone mean university students are the prey rather than the predators. Outside of school, there's a whole other world. (I say this not to prove a point - it's just an impression I get constantly, about how kind of airless my experience of "Chinese people" is if I stay only on campus.)
Story time: a girl I knew once did her teaching practice at a local middle school. Seniors had to do some kid of work experience to complete their degrees, and most of them did that. A teacher there - that is, a middle school "teacher", either an actual teacher or a member of the administration - said "if you want to make some extra money...." Turns out he was recruiting for a "tea house". The job was, sit downstairs and chat with the fellows who came in. Oh sure, upstairs there are small rooms with beds, but that's something else entirely....
There's something to the students' fear of "the social". All of them have it, or they used to. They used to talk about "going to society" as some fearful rite of passage.