Absent Parents

Is it better for a child to have a "negative" parent around as oppose to not at all? If an absent parent refuses to be in the child's life or if the absent parent is a bad influence, should that parent still have the right to "pop up" in the child's life whenever they feel like it? Or, is it more in the interest of the child to keep that parent away, but bring in other "good influences" to pick up where that parent lacked such as an uncle, grandfather or mentor? What do you think? Can someone else fill in where an absent parent leaves void or is that spot designated only for them?