Unfortunately, when the name “joyplot” took off, nobody in the datascience community was aware of the origin of the name “Joy Division”. As described in the book House of Dolls, joy divisions were groups of Jewish women in Nazi concentration camps kept for the sexual pleasure of soldiers. The band Joy Division took their name directly from this book and even quoted from the book in one of their early songs.
https://serialmentor.com/blog/2017/9/15/goodbye-joyplots
I wasn't aware of this either. Given the theme of Joy Division (the band)'s songs I think it's very fair to say they meant it ironically, but I do think it's fair not to name a beautiful plot type after something so horrible.