I would like to point out the Boston attack was the first successful bombing on American soil since 9/11.
I don't know if anybody else remembers 9/12, but the universal assumption at the time was that we would have to accustom ourselves to an ongoing wave of attacks, even if less spectacular. As in multiple bombings per year, and possibly per month.
In actual fact, of course, we went more than 11.5 years before the next successful bombing.
Given that there are at minimum some tens of millions out there who want to blow us up, I think that's a pretty damn good record. And I am offended at those who slander those fighting off our attackers by claiming the only possible way an attack could have gotten through was because those defenders were incompetent or complicity.
A good chunk of the world wants us dead. It is unreasonable to expect that none of their attempts will get through.
You ARE right. It’s disingenuous to get mad over 1 attack when we know so many want to do it. Especially lily when we know damn well of other plots that almost were successful.