Of course its their job, at least on the outside. However, some of it is rather debatable. Consider handle ties. Yes they are to protect untrained personnel, but is it worth it to idiot proof everything? Will DIYs adding circuits read the code to consider handle ties?
Which would hold water if AFCI actually did their job like GFCIs. Home fires have been steadily dropping, before the inclusion of AFCIs.
However, the publication makes note of something worth considering: "Simply because glowing connections are the cause ofapproximately 80% of electrical fires." If that is true, AFCIs are perhaps the worst possible method in stopping them as not all glowing connections arc, and those that do are hit or miss. AFCIs can not tell safe arcing from dangerous arcing, what guarantee is that they can differentiate dangerous arcing from safe arcing? Also add to the fact AFCIs don't look for series arcs until the 4 or 5 amp range...