Several weeks ago I came up with the following hypothesis.
Hypothesis: College students aren't actually relativists in a normative philosophical sense as many philosophy teachers love to complain about, but rather students look at philosophical questions through a sort of descriptive "pop social science" lens. That is, they don't understand the distinction between the question "What is the truth?" and the question "What do people say is the truth?" Very little in our broader culture or education system prepares them to answer the Socratic question, "What should I personally think is the truth?" beyond unargued personal preference.
Corollary 1: Go easy on your students, philosophy teachers. We are asking them to do something our entire culture (and maybe even human nature) either militates against or deems literally unthinkable.
Corollary 2: This maybe also explains a lot about why philosophy and the humanities more generally are so misunderstood, disrespected, and ignored by the larger culture.