Anybody has the right to leave his homeland and return as he pleases. This is never a gamble, it's an inalienable right. Besides, by December 1947 numerous massacres like that of Deir Yassin had already been perpetrated by the Jewish militias (with the clear intention of terrorizing Arabs out of their land). It is only reasonable that people wanted to put their families out of that kind of danger.
Yemen's Houthi rebels commit to peace plan in letter to UN chief, BBC reports (Haaretz)
from the article: Ethnic cleansing of Palestinians, or, democratic Israel at work