People are pissed with the establishment. People aren't going to take it anymore. In past elections they simply didn't vote, but this time they did: Voter-participation was at a record-high and at the same time the AfD rushed to success.
The AfD isn't here to last:
1. It was poor, disaffected people who predominantly voted for the AfD. And they will soon come to realize that the AfD is deeply capitalistic.
2. People voted for the AfD simply to send a shocking message to the established parties, not because they support the demands of the AfD.
3. The people who are unhappy with the establishment-parties want results. The other parties don't give them what they want and they hope that the AfD will deliver. But the AfD will be nothing more than annoying rightwing shock-jocks. The AfD won't deliver. Their voters will be disappointed and will leave again.
On the upside:
The Green Party state-government in 1 of Germany's 16 states just won a second term.