They are easier to define, but at what point does they start being a mortal sin ? This is quite vague.
Previous mortal sins were indeed more tightly linked with the individual while the new ones seem to be way more global (except for pedophilia and abortions)... polluting ? After what extent does it become "mortal" ? Being obscenely rich ? How much is "Obscenely" ??
But as the goal is to make people *think* about these matters, I don't think it is really necessary for them to be precise.
Here, drug dealing is about people ruining others lives and capacity of reasoning by getting them addicted to some dangerous drug, and I think drug dealers should be able to determine whether they are really helping others or not...