I understand what you're saying and I agree with you, but I think it's possible to hold an idea in your head and question it without automatically accepting it as truth. The only way to investigate an idea about a particular country, whether it be stereotypical or not, is by living there yourself or speaking with people that do (or researching, but first hand experience tends to give a more cohesive understanding). There is almost always a grain of truth to stereotypes, and the U.S does have a problem with gun violence in certain cities, though of course the extent of this is overblown in foreigners' perceptions, as you say.

Yeah I find that to be a really interesting thing about Japan, the way society strives to work together as a collectivist whole is almost the opposite to the discordant individualist culture of America.