As a university organizer at a very STEM focused state school, I suspect that students getting liberal arts degrees are more easily convinced to pursue a career in direct work. If this is the case, it could be because direct work compares more favorably with the other career options of those with liberal arts degrees, or because the clearer career outcomes of STEM majors create more path dependence and friction when they consider switching careers. This is potentially another thing to keep in mind when trying to compare the successes of EA uni groups.