Wrote these on the bus to school.
1. Fills the niches of society (Doctors lawyers engineers etc).
2. Teaches skills to people which allow them to be able to make changes in each field. (Vaccines, ebay etc)
3. Through teaching students to think, they can create new ideas that can create more things to make society effective. Things that can change the world. (Think internet facebook, telephones. This certainly coincides with 2).
4. Fosters understanding or Social change. (Think Ruby Bridges or The Little Rock Nine).
5. Informs and shapes citizens. (This is a huge one).
Remember, every one of these goals is related to each other. More reasons will be posted. I try to think in as broad and abstract a sense as possible so these reasons are almost too technical for my liking.