<p>In the case of California public universities, it's simply a question of serving the sheer numbers of qualified aspiring collegians. </p>
<p>The California plan calls for the top 12% of graduating high school students to find a place at a University of campus. That's almost 50,000 high school seniors each year. If thes students were to have to fit into only one or two campuses, those campuses would be comprised of about 200,000 students each!</p>
<p>So there are were eight campuses, now nine with UC Merced (assuming one doesn't count UCSF medical school, which would be #10, or Hastings Law School which would be #11).</p>
<p>Also Public universities tend toward reseach universities. The non-research universities at the Cal States (24 campuses), to which the top 40% are supposed to qualify.</p>