They are being deliberately disingenuous. I have been fighting the Left for over 60 years, and it is a characteristic--actually, particularly among the better educated Leftist--that they virtually always cherry pick the data they will discuss. The pattern is far too obvious to merely result from stupidity. Where the stupidity factor shows up--and it is not stupidity from low IQs, but rather from their fantasy goals, is in the selection of those fantasy goals.
They really tend to be air heads in those ways. If you seek, as Bobby Kennedy once put it, things that never were, and "wonder why not?"--you have a problem.
It's a little game they play, pretending not to understand the meaning of the 2A, so that they make you say it. Then they sit back and proclaim how nuts you are for thinking that the government would ever take the people's guns. Even though the government wants to take the people's guns.