To be fair to Germany, Hitler was the clash of two trains of thought. Should you punish a country for the crimes of its ruling class through fines and territory claims?
In medieval eras the country was property of the kings and the peasants were their rightful "tools", so punishing them was seen as fair, which is where the Versailles peace agreement came from.
In modern eras, the country belongs to no one and the ruling class is just that, the ruling class. Punishing people or taking land is seen poorly in international courts, regardless of what the country did in the war.
Hitler came to power because of how the allies treated the Germans after WW1. Had the allies implemented a restructuring plan, like it happened with Japan and Germany post WW2, instead of implementing border gore and impossible to pay fines, Hitler would have never been able to do anything, seeing as he was significantly unpopular. But if you trap a population between an impossible choice, this is what you get.
So you see, Germany couldn't have produced anything. The right wing might see a substantial representation increase in the parliament because current parties have been incompetent in handling migration over the last 10 years and refuse to listen, but the conditions that caused Hitler's rise to power are not currently met. Not even close.
Which is why i think you are not right in this matter.
Banning AfD would be incredibly stupid. Votes are a representation of concerns in a population. Ignoring the issues causing the votes and banning a party does not remove the concerns, just our visibility of them.
Europe in general needs to either drastically improve the integration mechanisms for migrants or reduce migrant throughput to levels which the current existing mechanisms are capable of handling. The current methods of just ignoring the problem and not giving a crap is clearly not being effective and thinking this is just a problem of ideology is exactly what's wrong here.
Banning parties is irrelevant, banning nazi symbolism is irrelevsnt, cordon sanitaire is irrelevant, declaring fascism illegal is irrelevant. Those are symptoms and if we only treat symptoms the problem just changes faces.