For this we have a Mekor in Chumash. Avraham sent Eliezer out of town to look for a wife for Yitzchak & Yaakov was sent out of town…”
Most of our boys are not of the caliber of Yitzchak and Yaakov, though they might think they are. Our Avos sent out of town because a) Avrohom wanted a girl ONLY from his Mishpacha, as the other girls in the neighborhood were not fit and proper to be an Eim b’Yisroel. b)Yaakov was FORCED to go out of town, to save his life, not to find a shidduch. He was fortunate to have mishpacha to run to from OOT, or our history might have been very different.