The unofficial online home for fans of the Old Dominion University Monarchs. Part of Collegiate Sports Nation (CSN).

I think it's pretty straight forward. They can easily narrow the gap between the folks who "say" they can do something and the folks who have done said project. This definitely creates a leaner group of applicants. Thus the University feels that whoever they consider, at least has the experience.
This is similar to job hunting: you can sometimes be excluded from further consideration because you don't meet a specific requirement. You may be able to do the job, but the potential employer doesn't want to hire an unknown. They "aint got no time for dat".