Are ancestors or departed spirits who receive offerings necessarily bad?

We cannot say that they are all bad. In my understanding, some ancestors and departed spirits are willing to practice spiritually and help people. If they cultivate well and continue serving people in this world, that effort also deserves respect. We need to understand their origins and consider their character, rather than decide whether they are good or bad from a single category.

A senior woman practitioner I knew once told me that she found a piece of driftwood, later dreamed of a woman, and carved an image to worship. She knew that the being she worshipped was not one of the great Bodhisattvas as people commonly understand them. She later recounted that the woman said the time had come to leave and asked them to go to a temple of the Golden Mother of the Jade Pool to invite a sacred image of the Mother Goddess. I viewed this as an example of cultivation and stepping back after completing one's work, and as an instance of a departed spirit willing to help people.

Do not first confuse a being's origins and then reject all deities when its behavior is unlike the great Bodhisattva you expected. If it is an ancestor, clearly say it is an ancestor. If it is willing to help, you can also learn what it actually does. Deities, ghosts, and ancestors need to be considered individually. Neither origins nor character can be left out.

Even if your first impression is that something seems wrong with a spiritual center, you still need to learn more. A first feeling alone does not establish who is worshipped there. I have also specifically reminded people that among the ancestral spirits I know, some earnestly help others and are good. After clarifying their origins, still look at how they actually treat people and conduct themselves. You cannot regard all ancestral spirits as malicious beings.