How does a couch catch fire, though? I suspect falling asleep on a couch with a cigarette is the main cause. Smokers want to die anyway, so I'd give priority to safety of children.
But what about the people living next door to your hypothetical smoker? It's a good idea to have fire safety regulations, for the reason that a fire usually will not just burn the person who caused it in the first place. (Whether this fire retardent helps prevent fires or not is of course a more difficult question...)
The article specifically mentioned this case. The chemicals they put in the foam would have absolutely no benefit if your apartment was burning because the neighbor's started. Furthermore, there is little evidence that the chemicals will prevent your sleeping smoker from burning the place down. Droithomme's comment[1] very much applies.
I've seen a number of fire videos as part of a training class. It is astonishing how fast a couch + room full of furnishings will burn: https://www.youtube.com/watch?v=ult6Biaf7oM. From ignition to flashover/fully-involved in 2-3 minutes. In a major urban area like SF, 5-10 minutes is a good response time for the first units on scene, not to mention the time to coordinate a fire attack, ventilate and flow water.
I don't know whether the claims in the article are well-supported or not (or what type of treatment the couch in the video had, as the videos are from the late 80s/early 90s), but I think most people don't realize just how dangerous a working fire in a single room full of ordinary furnishings can be.
That's where I think droithomme's comment comes into play. Where the downsides are so high, strong positive evidence should be provided and I'm not convinced it's there.
You have a point, we are back to needing more data. Living next door to a smoker, we have at least installed a smoke detector. But I suspect if it goes off it would already be too late.
