The trouble with these kinds of disingenuous replies is that nobody can take them seriously.
* You know what a 100 round drum barrel is.
* You know as well as anyone that automobiles exist, and that local laws can easily be circumvented, and hence has little bearing on how well a similar national regulation might work.
* "Significantly less if you remove big anti-gun cities from the picture". I'm sorry, but this is utterly irrelevant. Why would their regulations or lack thereof matter one bit in deciding whether the people killed by firearms in those areas "count"?
* "Murmurs of defensive firearms use instances in the millions annually" doesn't even attempt to sound evidence-based.
Pretending like you don't understand basic facts does not help your credibility. Although I suspect these talking-point replies are not meant so much to be taken seriously or responded to, but to merely decrease the signal to noise ratio in any discussion so as to drown out legitimate debate.
To take the remainder of your comment seriously:
For both good and bad reasons, people tend to take acts of violence, particularly indiscriminate ones, more seriously than, say, drug overdoses, where people, rightly or wrongly, blame the victim. Of course not all gun deaths are blameless, but neither do we want to pretend like suicides are unimportant.
Finally, we do try to take many of those other causes of death seriously. I get the argument of proportionality (we should spend 10x the effort on drug overdoses as we do on non-suicide gun deaths, I guess?), but unfortunately these stats are usually used in an attempt to say "nothing can be done".
No, something CAN be done. We can and should do better to prevent easily-preventable deaths -- whether or not the victim shares some blame in the death.
If we can save a few hundred or a few thousand lives, is that not a worthy goal? We are on a perennial march to make automobiles incrementally safer, but we haven't insisted that everyone climb into bubble-wrapped cocoons. Our regulators walk a line that sometimes errs to far this way or that way, we fight about it online, we argue with our representatives about it, but overall, progress is being made and lives are being saved.
I'd like to do the same here.