What’s so good about the water-saving propaganda of “please don’t let the taps weep alone”?

Personification is used.

Comparing faucets to people can better set off the atmosphere, express emotions, and make the things described have the words, deeds, thoughts and feelings of people, making them more vivid and realistic.

Personification is to compare something to a human action, rather than to a fairy tale. The things written must have human characteristics; words that represent characters cannot appear.