Why does the author state that the word 'criminal doesn't have a clearly defied meaning'?

PASSAGE – II

The passage is followed by a question based on its content. Answer the question on the basis of what is stated or implied in the passage.

There can be no sane discussion of "crime" and "criminals" without an investigation of the meaning of the words. A large majority of men, even among the educated, speak of a "criminal" as if the word had a clearly defined meaning. As a matter of fact, there is no such division, and from the nature of things, there never can be such a line.

Strictly speaking, a crime is an act forbidden by the law of the land, and one which is considered sufficiently serious to warrant providing penalties for its commission. It does not necessarily follow that this act is either good or bad; the punishment follows for the violation of the law and not necessarily for any moral transgression. No doubt most of the things forbidden by the penal code are such as are injurious to the organized society of the time and place, and are usually of such a character as for a long period of time, and in most countries, have been classed as criminal. But even then it does not always follow that the violator of the law is not a person of higher type than the majority who are directly and indirectly responsible for the law.

It is apparent that a thing is not necessarily bad because it is forbidden by the law. Legislators are forever repealing and abolishing criminal statutes, and organized society is constantly ignoring laws, until they fall into disuse and die. The laws against witchcraft, the long line of "blue laws," the laws affecting religious beliefs and many social customs, are well-known examples of legal and innocent acts which legislatures and courts had once made criminal. Not only are criminal statutes always dying by repeal or repeated violation, but every time a legislature meets, it changes penalties for existing crimes and makes criminal certain acts that were not forbidden before.