I think this is a root cause of a lot of the tension between law enforcement and inner cities... its a literal threat to their livelihood, legalities be damned. That makes sense to me.

I would be curious to see what happens to these infrastructures in places where marijuana has been legalized or decriminalized.

You should write a post proposing taking a trip into some bigger cities like Denver or Seattle to see if you can learn about the infrastructure before and after the legalization issue. That would be very interesting to see.