Much to the myth that a degree is just a degree with no real worth in terms of experience, the reality is actually quite different. As for most of those who go to university to get a degree, the duration of the course and the overall weighting in terms of degree classification after University are what really matters more than actual commercial based experience. One could say that it takes a special mindset to stick something out for the long haul to better themselves in exchange for a degree, and this alone should cast an image in the mind of the employer about the type of person they are hiring for their company.
Degree or not there is no real way of knowing whether the person a company is hiring is lying about their experience in the interview, and whether they are competent or not. When a company hires a graduate with a good degree classification the risk is far less and the person coming to the interview has exposure to that field and would have worked hard to produce the results that are shown with their classification level. In addition to that they would have learned aspects of the field that can only be learned through further education, and that is a very strong starting point to build experience on.
A company taking on a fresh grad that has good prospects will build a good relationship with that person and they will be a benefit to the company; they may make mistakes like any other employee, but better to be educated mistakes than mistakes made by somebody winging it without any background hoping it will work with a limited understanding.