It is... a meme? I think it is an explanatory construct that was invented by lispers who were facing the declining Lisp popularity back then in 90s. It was looking very promising, and then it just lost its steam and now almost no one uses it. One can imagine "Lisp is a bad language" as an alternative explanation, but most lispers do not (and didn't) agree and they prefer the Lisp curse, because it paints Lisp as a language that it too good for its success.

I'm not taking sides here, I love Lisp, though I don't use it anymore (except elisp in emacs, but it doesn't count). My point is that debating the name itself distracts from the actual issue.