This is an illogical question, as a question of quantities must be answered with a number. In this case, the the number of good librarians who have a sense of cleanliness. To find the answer, one would first have to define what a "good" librarian is, as opposed to a "bad," "average," "saintly," "fastidious," or any other kind of librarian, then determine how many of the "good" librarians have a sense of cleanliness.
If the questioner wants to know why a sense of cleanliness is a quality of a good librarian, then the question should be stated more like this "Why would a sense of cleanliness be considered one of the qualities of a good librarian?"
It may because our life is full of affection. Having cleanliness attracts many people and they believe they are from a good family. being beauty shows we are from a rich family which is too not good.
Cleanliness is health
Hygieia: Goddess of good health, cleanliness, and sanitation
One of the strengths of a librarian should be that they like to read. The librarian should also know how to do good research.
so people can work for you in a good business
The library charges a fine for each book that is returned overdue.
Cause cleanliness is next to Godliness
People learned that cleanliness was needed for good health
For what?
Cause cleanliness is next to Godliness
Cleanliness, no drugs, no harmful activities like gangs.
Cleanliness is important for good health.