Mags right, most of that is 4chan/Reddit.
Imgur is no. #1 in image hosting because of 4chan and Reddit.
The majority of the internet doesn't ever take national tradegies serious.
Boston Bombing is baby food compared to what happens in the Middle East daily, also people on the internet don't have to be their IRL selves, they dont have to have human emotions because they think there are no repercussions for their actions.
What you read was extremely standard fare for imgur and reddit theories.
It's because on the internet, you dont have to pretend to care like you do IRL, no one labels you an unemotional freak if you arent crying over some people you never met, just like when you hear about all those chillens in afrika dying all day err day, you dont care inside because you have zero emotional attachment to them, so they are just a number in your mind. The internet lets you not care and no one will really get buttflustered over it.
The simple truth is that gun crime doesn't affect the vast majority of law-abiding citizens. Therefore, the vast majority of law-abiding citizens push it to the back of their mind and think,
"It's not my problem, it's their problem."
Some facts that might explain why Americans care as little about everyday murders as they do:
54% of murder victims personally know the offender. 24% are killed by family members.
[1]About 12% of murders are done by people who are strangers to the victim.
[2]As much as 63% of homicides in American cities are gang-related.
[3]Rifles are only used in 3% of murders. Shotguns another 3%. Only 67% of murders are committed with any kind of firearms, at all.
[4]There are almost 3x as many suicides as homicides in America, and of those there are twice as many firearm-related deaths from suicide than by homicide. When you hear "50000 gun deaths in America", only 25% of those are homicides.
[5]Crime in America has been dropping sharply since the 1990's. America is actually more safe than many European countries.
[6]If we only consider the 12% of murders in the United States that are done by strangers[2] (ignoring that even a large percent of those are still gang-related), that is a homicide rate of about 0.4 per 100,000 people. That is a level similar to Japan.
[7]I hope you can understand why homicide isn't on the radar of most Americans in our daily lives.
tl;dr gun crime doesnt affect most law abiding citizens, while terrorism can and does