In The Odyssey, why is Ithaca still in danger after the suitors' deaths?

After Odysseus kills all the suitors who have been trying to get
his wife to marry one of them, Ithaca is still in danger because a civil war could break out.
Odysseus has come home and has killed all of these prominent men from the community, some in very
horrible ways. Of course, this could well cause a great deal of anger among the families of the
slain men.

This is what actually does happen in Book 24. Many of the
suitors' family members march against Odysseus, planning to kill him and his allies. It is only
the intervention of the gods that allows this to end relatively
peacefully.

So Ithaca is still in danger exactly because Odysseus
has slain the suitors, thus angering their families and making civil war a
possibility.