It's unsatisfying not because it's wrong, but because it replaces a tidy narrative, (a narrative which suggests a public policy many of us would like to support) with "it's complicated". I think you have the picture reversed -- the article is saying the problem is nuanced and complex when we'd rather believe it was simply the war on drugs.
I disagree. I think it's unsatisfying because it naively minimises the wider effects of the WoD.
I'm not American so I don't really have a vested interest in your prison population and why it's there, I only really know that compared to your population size it's huge.
I am quite pedantic though, and it looked to me like firstly it wasn't complete in its reasoning and secondly like 300K people out of 1.7M is still a very significant amount.
It has trends which suggest it's of little relevance, sure, but nothing particularly concrete. For all we know the homicide rate in the mid 80s (for example) may have dropped to a historic low without the WoD.
If not, can you help me understand why?
Not right now, drunk.
When you have a truly complex problem, the way to solve it is to pick it apart into simpler parts. If we start with ending the war on drugs, and the prison pop only goes down 17%, we can move on to the next reform.