Even if it is not Pitrubali, then why is it called Pithurtharpanam? Even if we are performing samarpanam to our mothers and grandmothers, why don’t we say matrubali or matrutharpanam?
Death is the separation of the soul from the body. After death, the body is either cremated or buried. After that, only the soul is left behind. That soul is what we call pitru. Atman, Pitru, Agni and Vayu are masculine sounds according to linguistics whereas Earth, nature are feminine sounds. The soul has female-male distinctions only when it actually resides within the body. When it leaves the body, Atman becomes a divine spirit, light and energy.
That’s why posthumous ceremony of our dear ones are called as Pitruyajna, tarpanam called as Pitrutharpanam and Bali for it as Pitrubali.
Poojari Manoj K Viswanathan