I think you're on the mark talking about them as toys for adults. I don't think most people want them because they really fear for their safety without, though the ability to defend oneself may be a bonus. My feeling is mostly it's just a fun hobby and it's also a clear signal of group membership.

I think your claim about there being a higher chance of accidental injury vs. self defense is probably wrong. The issue is a little muddy, but there are only ~800 firearms accidental deaths per year (0.00024% of pop.) and about 50,000 self-defense uses per year (https://www.bjs.gov/content/pub/pdf/fv9311.pdf)

I'm also not convinced about movies. I bet other places have very similar mixes of actual watching and the same selection given the internet.