To do that would defeat the purpose of Batman which was to rise above what's wrong still I can see where you're going with this. The only reason why the campus is so under-protected is because one reason plot convenience writers and editors are far too lazy to try and beef-up security so that students of the Xavier Institute for Gifted Youngsters will actually be safe. it's been an ongoing problem that Marvel still won't solve. in fact it's a cliche.