1] When things like this happen - it reminds people that they are Jewish. THAT is a Kiddush Hashem and a great merit for eternity for those who were murdered.
2] People are blaming Trump for the attack. When someone hates someone else enough - EVERYTHING becomes their fault. This happens in interpersonal relationships as well. When two people aren't getting along, they are liable to blame each other for things of which the other party is completely not guilty. Hatred makes people do and say crazy things.
3] They say that this was the WORST anti-semitic attack in the history of the United States. Think about how LUCKY we are: After CENTURIES of living in countries where pogroms were daily occurrences, where the law mandated terrible discrimination against Jews, where we suffered undescribable oppression on all levels, we now live in a country where THANK G-D we are completely equal citizens with equal rights. We are also thriving economically and have tremendous political power on all levels of government [the closest adviser and son in law of the most powerful man in the world, the president of the USA, identifies as an Orthodox Jew]. How amazing is THAT?? Just 75 years ago, millions of Jews were being systematically slaughtered, tortured and gassed and almost nobody made a peep. Today, eleven Jews were killed and everybody is talking about it and [exept for a few Neo Nazis] is horrified.
So what happened is a tragedy and our heart goes out to the families. But we should not forget the other side of the coin. We have been living in this great country since the 1700's and have never had it better in a foreign country in history.