Why is that? He won't be able to form government, as not Dutch party will form a coalition with him. At best, he will help Marie Le Pen to get elected in France. And then ....
Not sure if  many of Wilders' current cheerleaders will be happy with a number of European nations being governed by far right, populist parties. I guess that memories from Hitler's Germany and Mussolini's Italy have faded and the world is desperately asking for booster shots.
I'm sure that the current situation in Europe will bring memories to a number of people who lived WWII.
As the saying goes, be very careful what  you wish for ....