Suffering the Canaanites to maintain their cultural presence in the land constituted an invitation to intermarry with them, for they were the dominant culture.  Intermarriage, in turn, necessarily led to an adoption by the Israelites of the easier way of life – idolatry. 

Otniel, the first judge, represents the final link with the generation of Yehoshua and the elders that succeeded him.  Additionally, as a champion of the settlement of the land who personally battled the Canaanites and prevailed, Otniel recalls another dimension of Yehoshua's inspired leadership. Though he is a tribal leader - as opposed to Yehoshua - he is presented as a national savior as are many of the other judges in the Book of Shoftim. 

Courtesy of the Virtual Beit Midrash, Yeshivat Har Etzion