I think it is because my mum thought they were fashionable and practical when I was growing up in the late 80s. She used to dress me in them ALL THE TIME. It didn't help that she is Danish, so everything had to be extra scratchy wool. I just associated items of clothing with built-in necks as being itchy, constricting, too hot and making me too chubby.
Yet, things change. I am in the middle of a cardigan backlash and can't find anything to wear with my sleeveless 60s dresses from the summer except an old grey Zara turtle neck I got in some charity shop. It is still itchy and still highlights my double chin (surely it should be flattering, for the same reasons as Boy George used to paint his neck grey?) but it has a satisfying 70s look.
