Ikigai is occupation-centric, hands down.
A mother might say that her reason to live is to watch/nurture/care her kid growing up. Well, she loves the cause (the kid); she may be either a good or bad parent; in the big picture, the world might not need that particular kid; and parenting costs bunch of money, time, energy, understanding, patience: all kind of resources, in short.
So, parenting is either mere love or passion. But I will take "my kid is my reason to keep on living" as wholly valid reason--not an excuse--to live your life.