AZ, what do you propose to do with these younger bochurim who you propose start dating earlier? Are you planning on giving them a class on maturity, social skills and the difference between men and women? The reason boys are not getting married at the same age as young women is plainly and simply the fact that they are not ready. They can barely take care of themselves appropriately; to take on the responsibilities of a mature, loving, caring and unselfish married relationship and parenthood is too much to expect of bochurim that are not mature enough to handle those REAL LIFE responsibilities.
Girls can basically get married straight out of High School, that is not the case with boys.