Describe how hallucinogens are not a drug of abuse in the classical sense of the definition

The question doesn't provide the "classical" definition of drug abuse, so I'm going to work with the following definition of drug abuse. Drug abuse is the habitual taking of addictive or illegal drugs. HealthyPlace.com defines it this way: "Drug abuse is an extreme desire to obtain, and use, increasing amounts of one or more substances."
I would like to point out that both of those definitions point toward using and "needing" drugs because of an addiction. I think this is what the initial question is asking about in regard to hallucinogenic drugs. This category of drugs includes drugs that alter perception, thoughts, and feelings. They can cause hallucinations—false sensations and images that seem real. LSD, PCP, and ketamine are all common hallucinogens. In regard to addiction, not all hallucinogens are the same. Many of them are addictive; therefore, they would fit the classical definition of a drug that leads to drug abuse. However, LSD is not considered an addictive drug. It doesn't cause uncontrollable drug-seeking behavior. While LSD might not cause addiction or lead someone to immediately start abusing it the way that other drugs might, that doesn't mean it can't be abused. For example, LSD produces tolerance, so users that repeatedly take the drug must take higher doses to get the same effect.
http://hallucinogens.com/are-hallucinogens-addictive/

https://www.drugabuse.gov/publications/drugfacts/hallucinogens