Math and Sci scores are more important than the reading and writing. WP is a defined as an Engineering school.
defined by whom? Though I think I know what you mean, I find that overstated. The Academies confer a Bachelor of Science degree, and not a Bachelor of Arts degree, so I agree with your basic point that Math and Science scores are probably given more weight than the other sections. As is the case with almost any school in the US, a BS degree requires as a foundation a full year each of Calculus, Chemistry, and Calculus-based Physics... so that is why both Math and Science proficiency are important for incoming cadets.
Regarding the BS degree, this is from the Wiki on the Naval Academy:
"President Franklin D. Roosevelt signed into law an act of Congress (Public Law 73-21, 48 Stat. 73) on 25 May 1933 providing for the
bachelor of science degree for Naval, Military, and Coast Guard Academies."
I didn't know where to find the % of degrees by major on the USMA website, so I found it on the USNWR site
http://colleges.usnews.rankingsandreviews.com/best-colleges/west-point-2893
Five most popular majors for 2011 graduates
Engineering 21%
Social Sciences 18%
Foreign Languages, Literatures, and Linguistics 9%
Business, Management, Marketing, and Related Support Services 6%
Engineering Technologies and Engineering-Related Fields 6%
Looks like 27% of cadets graduate with some form of Engineering degree. That of course means 73% do not!