According to Pew, roughly 29% of Americans say the USA is the best country in the world, when asked if it's the greatest, one of the greatest, or worse than other countries. Among people 65+ years old or politically conservative, that number is 44% and 47% respectively.
That's a relatively
new view.
You're not defending atrocities, but you're arguably helping to enable them. It's objectively true that the kind of gun regulation that has been proposed reduces the frequency of these kinds of atrocities.