Yes. Propaganda works. I'm not sure what your point is.

The problem with Denazification is that it wasn't very thorough. The Allied (and US's in particular) post-war plans was to ramp up defensive capabilities for the Cold War that had slowly manifested itself during WW2. While several high ranking Nazis were executed or at least tried, some fled the country, some died and some were recruited by the victors (e.g. Operation Paperclip) it was considered more important to have "qualified people in charge" to rebuild the country than to avoid putting Nazis back in their positions of power, so back in positions of power many of them went.

Modern Germany made a big show of combatting Nazism but due to the Cold War for a long time that had to go hand in hand with combatting "communism" (e.g. banning the KPD on a legal basis that is today considered to have been largely bogus), making the messaging incoherent by failing to address the disease (protofascism) rather than the symptoms (e.g. symbology).

But my point was that calling the Nazis popular at the time is in the most literal sense survivorship bias. While most people think of the people the Nazis killed outside of Germany when they think of their victims, they also killed and displaced a lot of German residents. So even without the propaganda and the appearance of prosperity, it's iffy to call them "popular" when the people they were very much unpopular with largely died, fled or were imprisoned (and in some cases continued to remain imprisoned after the war, like those accused of homosexuality or being too left wing).

The reason I object is that Nazis (and their ideological analogues in other countries and times) aren't popular. They have to lie, kill and oppress in order to acquire and maintain power and they only become popular with lies and scams: selling a narrative of a chosen people and raiding society for a fiction of wealth. It's an utterly self-destructive ideology and requires constant purges and the designation of new enemies within.

We have culturally gained an understanding in the West that the Nazis were the bad guys of WW2. Thanks to banning their symbols in countries including Germany, and thanks to a very productive movie and television industry, especially in the US. But you will still find large minorities in many countries that would find the fiction the Nazis created about themselves appealing as long as you change the labels and avoid obvious historical details. And if you give them the right justifications, they too will likely think exterminating an entire minority could be "regrettable but necessary". That's a problem.

Sorry if I'm rambling too much. This struck a nerve because the claim "the Nazis were also popular" is too often used to suggest that the Nazis gained power through being popular (which is often used to denounce any political position that's popular as inherently worthless or dangerous) or that there was something unique about Weimar Germans making them so naive or wicked to support the obviously evil Nazis (which is often used to deflect any notion that it could literally happen here/again because we're smarter and morally superior). Modern Germany's treatment of the Third Reich tends to mix the two by insisting that "the Nazis" were all just inherently evil somehow (which means any modern politican who is politically aligned with them can't be a Nazi) but "the Germans" supported them because they were promised good things (so promising good things is deceptive and we simply can't have nice things).