If there was a closed campus then no one would feel safe if someone finally came in there would be nowhere to go. If there parents were right there they would feel more protective then being not protective with a family member. That's why closed campus is bad to have.
Overall it is not bad to have an open campus.Students must learn how to conduct themselves and this is a good way to practice in a somewhat protected environment.Young people will never learn how to stay on time if they are not given any practical freedom when they are still in school.
Personally, I attend a college that offers open enrollment, and I think it is a great thing. If someone wasn't the greatest student in high school, and still wishes to pursue an education, they should have options for colleges. Obviously, they will not have as many options as an honor role student, but options none the less.