Hmmm..well, I've always seen it as a popular idiom that harks back to the principle of Ockham's Razor:
'the simplest explanation is always the best'.

D

this might be true in mathematics...Okhmans razor says you should pick the explanation that assumes the least...I would say that someone is assuming a lot by concluding someone is a drug addict..or a criminal..based on other qualities he shows that don't prove that point in anyway..it's just social stereotypes or something from the addict or criminal archetype theories...yeah good for math not so much for looking at someone through your own kaleidoscope of judgment to connect dots.

A cute little quote