It‘s important to note that this article talks about the protests on Wednesday and Thursday.
The much larger wave of protests happened over the weekend. For example, this article talks about between 6.000 and 13.000 participants in Berlin.
Today there were between 160.000 and 250.000 in Berlin alone, and many more in other parts of the country (detailed statistics are available here, though unfortunately only in German).
I hope we can keep up the momentum. There are enough right-wing opportunistic populists in power all over the world right now. We really don‘t need one in Germany as well.