MFA department literary magazines are run by young, enthusiastic students and their professors, which means they are more than happy to nominate the stories they accept for Pushcart and other national prizes.
The second reason is that any agent or editor who has graduated from one of these programs in all likelihood has a subscription. (I know of at least one case in which a short story submission to a university literary journal resulted in representation.)
The third reason to consider submitting is that these journals have a "captive audience." Students, professors, and university staff read them, and depending on the size of the university that can be a lot of people.
Click on the link below for 130 MFA department journals accepting submissions. (This program does not allow tables.)
Mega-List of University Literary Journals Accepting Submissions in Fiction, Poetry, Art, CNF