Why is the GPA for Muhlenberg so low?

I looked up the average GPA for Muhlenberg and it is a 3.3, yet the acceptance rate is only 48%. I know it has a good reputation as a LAC, but am wondering what these statistics say about the school in general and the type of students who attend. Are the students intellectual? Are the academics rigorous?

Current student college GPA or admitted student high school GPA?