First, universities are first and foremost schools. The most basic function of the school is to let students receive education safely on campus, and ensuring campus safety is one of the important tasks and responsibilities of the school. If the university is open, we can't guarantee whether the people who enter the university from the outside are safe enough, and whether it will cause potential safety hazards to the personal safety of college students. These uncertain factors will bring a burden that cannot be ignored to the security of universities. The main service groups of university campus environment are college students and university teachers. As a closed educational place, a university should not be open to the outside world.
Secondly, college students are young people who have just graduated from high school. They are about twenty years old, and their minds are not mature enough. They are easily influenced by all kinds of bad atmosphere in society. As the ivory tower of college students' study and life, universities should try their best to keep a clean and pure reading experimental environment and cultivate students' bookish spirit and vitality. The entry of social workers will easily make the university environment impetuous. Of course, perhaps the advantage of opening several universities is to let students enter the society as soon as possible, but I think that premature contact with society before students' mental maturity will make immature college students easily go astray. These are not the phenomena we want to see.
Thirdly, the bad thing about the opening up of universities is that we see many parents taking their children to play in universities, but they often don't obey the slogan of no talking loudly in the corridors of university teaching buildings and ignore the advice of staff, which will cause great trouble to university teachers and students who are attending classes and affect their studies. After all, the real masters of universities are college students.