Because, if the people are not armed with lethal force, they cannot defend themselves from the government.
Governments essentially claim a monopoly on force. How can lethal means defend you from the government better than non-lethal means do? The only difference is that you either end up killing members of the government or not.
Because you made the statement "your main argument is" and then proceeded to address only the issue of self-defense, and none of natural rights, [...]
I didn't address the issue of natural rights because not only is it irrelevant to the point I am trying to make but I also never disagreed with it in the first place. Nothing - and I mean
literally nothing - I said so far has contradicted the idea that people have the natural right to defend themselves from harm or that guns are acceptable tools to provide said defense.
I don't see what point you're making here; do you think that it's difficult for people to get a hold of non-lethal weapons? There isn't anyone opposed to gun-control who is going to claim that we shouldn't have access to less-lethal weapons, and it's generally much easier to acquire a non-lethal weapon than a lethal one (and also easier to legally conceal).
I'm not an insider on the subject since I'm neither american nor do I know a lot about weapons. But just going by general media coverage one gets the impression that lethal weapons - guns in particular - get a lot of promotion and the general sentiment seems to be that "a weapon to defend oneself" is synonymous with "a gun to kill with if needed be". Unless I'm mistaken non-lethal weapons are not being promoted on a level anywhere similar to that and I'm not sure why. I think it'd be a good compromise solution for both parties as the natural right to defend oneself is granted while there's still an acknowledgement that there
is a problem with guns in america [and let's be real - you really can't deny that there is, can you?] that people are interested in finding a solution for.
My point is that non-lethal weapons are not given enough attention to [something you didn't directly respond to though I made the point earlier already]. They are a viable compromise solution with more pros than cons overall and I don't think the government or the general public seems to be aware of it all that much. If the Obama adminstration is in favor of gun control in order to limit shootings then the promotion or even subvention of non-lethal weapons must surely be in their interest as well as they would achieve exactly that - a limit of gun related deaths - without limiting the rights of people.
The burden of proof is on you to show that non-lethal weapons are a sufficient substitute (and, more importantly, to explain which non-lethal weapons are sufficient, since arming people with pepper spray probably isn't what you had in mind). Keep in mind that less-lethal weapons are either close-range (e.g. pepper spray) or shoot with less force at a lower velocity (e.g. bean-bag rounds or rubber bullets).
This is the kind of weapon I had in mind:
If it's possible to pierce somebody's head with a sharp bullet and kill him then it's also possible to fire something that doesn't cause the target to die but to make him lose consciousness or paralyze him or something similar.
Now I know, I can't say whether such weapons actually exist or not but as far as I can tell there should be no reason on why they
couldn't exist by now - unless, of course, non-lethal weapons are so out of favor that few seem interested in investing into that field. Which would be contradictory to assume, since my "theoretical solution" would
be making investments in non-lethal weapons. So, what other reasons are there for non-lethal weapons to be less effective? I don't see how it's in any way impossible to create non-lethal weapons that are as effective as a lethal weapon. So by all means, please show me how non-lethal weapons are principally ineffective, compared to lethal weapons.
And even if they were less effective you'd still have plenty of pros: some people may be unable to shoot with a weapon they know might kill the target but they could dispose him with a non-lethal rifle. If such a scenario were ever come to pass a lot of harm could be prevented. Another big pro is that the target will not die in case of an accident.
Now, let's for a moment assume the following scenario with the idea in mind that you are still right about non-lethal weapons being less effective: another school shooting were to happen but this time around all the employees of the school [teachers, school caretakers, janitors] were armed with non-lethal firearms. Would you agree that the chances of preventing a tragedy would increase
massively? Would you still claim that lethal weapons are better suited to prevent gun-related deaths in such a scenario?