Oh, that's not specious at all. I just think an armed populace would be pretty ineffectual in terms of defending itself from the US government if the US government were intent on oppressing people. I also think the risk of the US government becoming overtly authoritarian and brutal--despite growing executive power, surveillance and hostility to encryption--is pretty low.
No doubt people do need protection from government in some form, but inclusive democratic institutions are far more effective at establishing and maintaining that. At least in my mind.