I think it's not related whether you are going to an university or a college, the majority of students that handle to get admission in a public university are good students and have no issues with their profiles, for example to get admission in an university at an undergraduate level you need to supply letters of recommendation, marks , provide information about gaps, etc.
So that's why you see that most students that got admission in an university got their visas, it's not easy if you are a bad student to get admission in a public institution(university)