Why do the witnesses shun anyone at all?

my parents raised me to be one of jehovah's witnesses- (i'm in my 30's now.) i never baptised.-though i felt the very common pressure from the congregation and peers. i have seen in a lot of situtions where this can tear apart families when all the person who was disfellowshipped needs is help. i also find it very strange that they find it acceptable to ociate with me , never being baptised yet completely disregard the meer existence of someone who was disfellowshipped. it doesn't seem like that's what jesus was trying to do in fact i thought they were the ones he sought out.