The primary driver for this is the concept of
面子 (miànzi) - “face”, which represents a person's reputation, dignity, and social standing. A direct refusal, criticism, or sensitive request can cause someone to “lose face,” leading to embarrassment and damaging the relationship.
暗示 is the tool used to navigate these situations gracefully. It creates a buffer, allowing the other person to accept or reject the implied message without a direct confrontation.