Here's where I see a dichotomy in your thinking: Fear sells, yes; people want simple answers to complex problems, yes. Cycling in English speaking countries is generally seen as dangerous for some reason, not because helmet manufacturers managed to sell it wholesale, but because this perception exists outside of the helmet debate. It's the same thing that fuels 3' passing laws, and bike infrastructure advocacy. So while helmet promotion might play into the dangerization of cycling, it is certainly nowhere hear wholly responsible for it. Shows up in way too many other parts of society, aka nanny state-ism, for it to be only the fault of the pro-helmeteers in cycling.

Right?

So then there's the helmet companies, taking full advantage of this perception that cycling is dangerous. Who is to blame them? And if someone who would not otherwise ride a bike w/o a helmet mistakenly feels protected enough with a helmet to venture out onto the "mean streets," then helmets -- wrongfully seen as a panacea for bike safety -- have encouraged riders...

While certain countries, provinces, and localities have passed mandatory helmet laws (MHLs), the vast majority of the planet is free of such nonsense. If this is central to the debate, then it's a weak debate... And the various kinds of posts in this particular thread indicate that it is a very, very low concern even with geeks who like to debate whether angels on the head of a pin should wear helmets.