I don't think there's no other conclusion I come up than their lack of interest for the team to create them at all. With the recent expansion pack, there was and is the right opporunity to patch firefighters, since Island Living provided a feature in Sulani where friendly citizens put out fires in active household's lot. Before that, when Kleptomaniac trait was added via update, developers could have just created a spawning NPC with that enforced trait behavior to appear at a certain time pushed to swipe things.
With the existing mechanics that could been used to develop NPCs pushed to be act upon, you would think that we get the feature that's been highly requested by now through out the five year passed mark. Or does anyone don't think so though, but would like to convince me otherwise? I think it's a bit shame that developers seem to refusing spending resource on said NPCs that would receptionally pay off.