Well, according to an interview with Papa Gaghan, that during the leg where the Weavers won, they isolated themselves. This caused the teams to not trust them. It doesn't help that they have exhibited strange behavior like dancing around in the Waffle Place (just before the space camp roadblack) and complaining loudly on the bus like they're "inaaapi" and the constant snubbing and mistrust that the mother has treated the other teams.
It also doesn't help that they think of themselves as "Christian" yet make fun of other people behind their back and being in general very self-righteous and hypocritical.