The weather is good year round. They take him to the beach, etc. He will also get a better education at USC over utah.
How can utah compete with that? BYU at least has the draw of an LDS based school and what an LDS kid will be exposed to at BYU, he cannot get at any other university. I know utes try to compare themselves to BYU telling LDS kids "you can get a LDS based experience here" and then telling non-LDS kids "we are nothing like BYU."