That article was written by Scott Burnstein, who posts over on the Real Deal. I suppose it depends on how you define both "active" and "family."
Activity? The last significant bust involving the Detroit mob was back in 2006. Mainly a gambling and loansharking case. Then you have to go back 10 years to 1996 when Tocco and a bunch of other guys were rounded up.
Family? Scott believes there is 40-50 members there. I have to disagree for any number of reasons. First, the families in New England, New Jersey, Philadelphia and Chicago each have about 50 members but far more activity than Detroit. And I don't buy the argument that Detroit has found a way to avoid law enforcement detection while every other family hasn't. Second, in 1996 the max estimate what 30 members there. It's highly unlikely that a family like Detroit could increase that much in size over the past 15 years. Scott cites rumors about a couple of making ceremonies in recent years but it's not much to go on.
When judging which families are still viable, I choose to use the RICO standard - an ongoing pattern of crimes conducted in behalf of an organization. In my view, Detroit doesn't meet that standard anymore.
While I usually agree with Ivy's post I have to disagree with the assumption that because there are not as many arrests as being proof of less criminal activity. Do you really think all criminals have the same intelligence base and are equal in terms of being able to avoid prosecution? Do you really think all law enforcement agency's and the people in charge of them are all equal in intelligence and ability? Just as with any other job and regardless of if you or on the law enforcement side or the criminal side, some people are much better at doing there job than others. The lack of arrests could easily mean the Detroit mafioso are better at avoiding detection, or it could mean that the Detroit law enforcement agents are simply not as good as the ones in NY or Chicago, or that the person in charge wants to focus resources on other criminal elements such as street gangs rather than on senior citizen mafioso. Are all lawyers and detectives equal in ability? Despite what politicians might tell you men are NOT created equal. Another factor one has to look at is where the resources of local law enforcement are allocated. If I am not mistaken Detroit has one of the highest murder rates in the USA and has a very high amount of gang activity which would demand more attention from law enforcement than say a place like Providence.
If there were 30-40 cities with active OC Families it would be much easier to draw a median and make assumptions based on average but there are what 5-6 North American Cities with OC families? I'm sure all the active families have different strengths and weaknesses and perhaps in comparison to the other families, Detroit has figured out a way to avoid detection by law enforcement that the others have overlooked, at least for the time being.
Of course this is all speculation and is in no way meant to be disrespectful towards Ivy