It get's more attention because it's guests attacking their host nations citizens. Nobody's denying that our native citizens also commit crimes against each other, but when you open your doors and allow people to come in believing you're doing good and being generous and then they take advantage of your trust by attacking you, it's worse. It's more personal and more egregious. That's why people are so angry about it.
Because, per capita, it is happening mostly by illegal immigrants. Either way, if we have a problem with sexual assaults and them going unpunished, importing people from anti-woman cultures is a terrible idea. Let's not add to a problem.