Literally the least surprising political act of recent times.
Merkel sells the Germans mass immigration, the actual German people see their leaders cover up immigrant crime (cologne etc) and rally against what they see as the common factor of this 'protected class' who commit crimes notable by cultural difference ie a beheading or the loss of a hand for thievery is normal in hardline muslim countries whereas its hated in Europe so we notice more. Same principle, they have different consent laws and opinions of 'legal age', roles in society and cultural practices which mesh badly. I won't engage the debate about criminality as a whole, I have no idea how they think (though the crimes seem opportunistic and in rejection of the law, therefore I'd argue intent criminality), but the point is their 'crimes' are abhorrent by European standards.
This perception of a privileged class over the indigenous population whom the people cannot legitimately politically oppose leads to partisan simplifications ie ban mosques, ban the burka. When sensible solutions or ideas are shot down as 'racist' and 'islamophobic' people stop caring and go for the lowest common denominator, x is different so end x practice. This is obvious to most people, but not politicians. People judge by their immediacy.