I would also add that the foregoing rationale is equally true as applied to large public universities. The question is, which one? Graduating from Cal or Michigan or UVa or UCLA is much different than graduating from, say, Mississippi State or Kansas State. The idea that attending a LAC, all else being equal, is somehow a disadvantage in applying to graduate school, in area, is not well founded and a bit absurd. I don't know anyone who understands how these things work who would remotely agree with that notion. In fact, if anything, there is a view out there, with which I don't entirely disagree, that it is often an advantage. There are many people who still view a rigorous liberal arts education at a small college to be the gold standard in undergraduate education. This is a very debatable topic, so I don't intend to get into a side-debate about it here. But kids from schools well outside of the Williams, Amherst & Pomona group of tippy top LACs go on to elite graduate education in the sciences in droves.
Otherwise, we'll have to let the cohort of applicants from Middlebury, Wellesley, Swarthmore, Wesleyan, Claremont, Haverford, Bowdoin, Colby, Vassar, Colgate, Hamilton, Smith, etc. etc. that they face an uphill battle. Of course, that is absurd.