Don't know why it has a low ranking. Where did you get the ranking? BW or USNEWS? But I will say, ranking is only a reference. If you were in Bay area, everyone will told you that get a MBA from San Jose State University.You can't find out its ranking in the top 100 list. It all depends!
I know its Real Estate is very good, and it claims the program to be a top 3 in US and in the Vault Career Guide for Real Estate mentions it along with Wharton, Haas, MIT, and the Ohio State U.