Under almost all scientific evaluations of drug classifications, several currently prohibited drugs are considered less dangerous than alcohol in under every measure of judgement.
It should be of common belief that all laws should be FAIR. The current social situation and social norms should not influence laws. Marijuana use shouldn't be a grounds for arrest if alcohol use is not.
Alcohol has a high abuse potential and no accepted medicinal use but remains outside of Schedule I of the Controlled Substances Act. Why should people be arrested for the use and possession of marijuana, LSD or Psilocybin mushrooms, which cause less dangerous impairment, physical, and psychological harm than alcohol and tobacco? Either add alcohol or remove these and other less harmful drugs from the Act.