The exile of the ten tribes ultimately leads to their disappearance as a distinct group. The Assyrian policy of population transfer brings in foreigners who worship idols and since the Land of Israel does not tolerate sinners they are attacked by lions. They are saved not by rejectiong the idols, but by accepting God as supreme. The strict monotheism mandated for Jews is different from the level of belief required of other nations. For Israel, icons are absolutely forbidden, even when they serve as intermediaries to God. This is the primary sin for which the inhabitants of Shomron were exiled. However, for other peoples, idolatry and other gods are tolerable as long as God is recognized as the supreme deity, even while other gods are worshipped alongside Him.

The status of the Shomronim - Samaritans is a long historical debate spanning from the period of the rebuilding of the second Beit HaMikdash, in which they were not permitted to participate, and continuing into the time of the Sages.  

Courtesy of the Virtual Beit Midrash, Yeshivat Har Etzion