They do? Im guessing that you're not talking about heroin or Crack addicts that would rather spend their money on more Crack or heroin. Do you mean cannabis users and the munchies?
"Druggies" ?
By that do you mean occasionall users or addicts ?
One of the effects of marijuana specifically is to heighten the senses, including taste - I haven't heard any reports on cravings for sweet things by users of other substances..