As John Laurie explains in his economic study: Spring Break: The Economic, Socio-Cultural and Public Governance Impacts of College Students on Spring Break Host Locations, Spring Break is more cost than benefit for the communities that act as destination hotspots.
This is largely the case, because college students are broke, cheapskates, who spend lots of money on cheap booze, but sleep five to a room in discount hotels, while they cause and/or attract more criminal activity than they are worth.
In other words, the only industries that can count on reliable stimulation from Spring Break are dive-bars and law enforcement, the latter of which is quite expensive for locals.