Exactly....If they wanted to say "the right of the people to keep and bear arms shall not be infringed" they could have left it at that
But they chose to tie it to well regulated militias
Zackly --- and "a well regulated Militia" is hardly the
only paradigm under which Arms can be used ---- although hunting shotguns weren't invented yet, nor was the revolver, nor was the Minié Ball; even simple dueling pistols were just then getting standardized ---- so their concept of "Arms" would have been a fraction of, and infinitely more limited than, ours is. It stretches credulity beyond belief to imagine that they would have meant to include all of the future technologies up to and including shoulder-fired antiaircraft missiles and land mines and nuclear bombs etc.
So it's reasonable to note that at the time the 2A was written the use of "Arms" was limited to (a) war, its original purpose, (b) a well regulated Militia or (c) dueling to settle a personal score. The idea of a sniper sitting on the top of the local grain mill picking off random strangers ---- simply did not exist, as the technology to do that didn't exist.