Vanderbilt says that about 42% of undergraduates are in fraternities and sororities, which is a relatively high percentage compared to most colleges (but lower than at places like Dartmouth, Bucknell, Washington & Lee, and Depauw).
Given the student’s preference for less partying/alcohol, high fraternity and sorority presence may not be desirable. Also, fraternities and sororities on many campuses tend to be racially (self-)segregated, which goes against the student’s preference for diversity if that is true on the given campus (can be investigated by looking at chapter photos and the like).