That's a lot of condescension coming from the guy who thought he would look like a "suave gangster" while performing door to door pot deliveries.
He also suggests they were spending $60/day on weed.. wouldn't that be at least $1200/month? He had few enough clients that he never saw the same first name twice, so his clients were probably earning more than he did.
As easy as it is for him to judge the pill clients, he could have made an effort to think of reasons why his wealthy clients were hooked. People get addicted to opiates all the time, and its not always drug dealer delivery guys who introduce them to narcotics.. sometimes its a doctor.
And perhaps, at some level that was the point. The lack of self awareness is endemic to all the participants.
I think it was intended as adorable, humorous self-derogation on authors part.
Interesting story though.