Lol, as if big tobacco and cigarette smokers wouldn't use their own set of facts to reduce that 400k number to 0. Cigarettes don't cause cancer because derp de derp derp derp. Wake up sheeple its all lies perpetuated by the government so they can tax your cigarettes! Etc.
But you know what the real difference between those numbers is? Well, how about this: How many people have been convicted of Murder 1 by cigarette? Because yeah, killing someone on purpose puts things into a different category than deaths by accidents or unhealthy habits.
Now, secondhand smoke deaths ARE an issue. And that is being addressed, if slowly. Smokers forced to stand outside where they can't fill up a room with their poison aren't killing anyone but themselves.