Actually, it’s the opposite. Consumerism is one reason LACs are so loathe to expand. For example, Wesleyan has barely budged by a few hundred students since 1981 despite the fact that the general college student population has nearly doubled since then. LACs are fully aware that they are not for everyone.
And, I’m absolutely flummoxed by how often people confuse the liberal arts with majoring in the humanities. One of Wesleyan’s oldest departments is Astronomy; one of its most renowned alum is Wilbur Atwater, the inventor of the first calorimeter (a science building at UConn is named after him); Amherst has four Nobel Prize winners to its credit, two of them for medicine and physics.
So, I’m not even sure I accept the premise of your question.