Maybe in your small bubble. The 2CV was, and is, as much of a style icon as the Käfer (Beetle), the Topolino, the R4, the Mini, the Cinquecento and other greats of its time. As a matter fact, it's undoubtedly one of the titans amongst outstanding examples of automobile design and culture. Where the heck have you lived?!
The 2CV was designed from the start as one of the cheapest cars possible. Ultra cheap things are rarely considered "style icons" during their heyday.
The Dutch Wikipedia article explicitly calls it Lelijke Eend and the German one has some references to "das hässliche Entlein" and how Citroën tried to sway people to a more favorable nickname. There is also a book with it in the title.
Again you may be thinking of the DS, which was Citroën's flagship model and its fender skirts were the ultimate expression of cool.
I have never, ever in my slightly more than forty years on this rock heard Germans refer to the 2CV as "hässliches Entlein", let alone their 2CVs, and especially not in colloquial conversion. It was always just Ente. Same goes for printed materials, e. g. magazines, books, etc.
As a matter of fact, I believe it's the opposite of what you imagined: The "ugly duckling" designation was used from time to time either by ignoramuses (e. g. in older magazine headlines), or, in an ironic fashion, by some of the machine's owners.
> Again you may be thinking of the DS, which was Citroën's flagship model and its fender skirts were the ultimate expression of cool.
No, I'm talking about the 2CV. At this point I should mention that I'm East German. Citroën cars, compared to other Western makers, were relatively common where I grew up during the 80s. The most common one before the Wende? That's right, the DS!
> The 2CV was designed from the start as one of the cheapest cars possible.
Utilitarian/economical design and beautiful styling are not mutually exclusive.
EDIT:
> The Dutch Wikipedia article explicitly calls it Lelijke Eend and the German one has some references to "das hässliche Entlein" and how Citroën tried to sway people to a more favorable nickname.
So... according to the German wiki's source the blame goes to an early impression from some random Dutch journo. Quickly shortened to Eendje, already before the car made it to the German market. Where it was virtually always just called Ente, cause nobody uses more words in colloquial speech than they have to. Especially not with a mouthful like "hässliches Entlein".