@HolyDemon A manga needs to be at least somewhat entertaining.
I mean, good manga, and in entertainment in general, to be successful, you have to create something entertaining, that sells well and that have some depth/a message.
It would be difficult to create an entertaining plot revolving around sorting trash.
On the other hand, it's pretty easy to do so with topics revolving around sex, violence, death, and so on...
Exchanging drugs for profit elevates you by destroying others and so hurts yourself. But what if you are in the business because you respect and want to be close to a person involved. Are you helping by give those stuck there a chance to have interactions with someone not interested in profiting off of them.