re: There was no shooter at OSU

You are right. The founders understood the ability to defend ones' life and liberty from individuals as a given. Their focus was on the right to also defend those things from a tyrannical government, which is why the 2A was written in the first place, as an additional (some would argue the primary) check on government overreach.

The right to individual self defense shouldn't even be a talking point; it should be accepted by everyone. Firearms are needed by citizens to keep the government from stepping on their throats.