I think this is a common misconception about Peddie. The humanities department is second to none and the quality of the faculty is outstanding.
In addition to all the core courses, both the History and English departments offer a large and ever changing selection of interesting electives each year.
As for creative writing, students may apply to the Signature Program in Creative Writing at the end of their sophomore year which culminates into a 50 page capstone project by Senior year. This is much like their showcase EXP/Lab Research Program for science.
There are plenty of artsy/non-sporty kids at the school, including some extremely talented musicians.