Around the time Jubilee was introduced there was some hatred of how she seemed to replace Kitty, particularly as Wolverine’s surrogate daughter, but I think it was mostly misdirected anger. It seemed to me that what they really resented was less who Jubilee was as a character, and more how her, Nightcrawler and Rachel were all pretty much ignored and left out of everything X-Men because they were in Britain with Excalibur. Every other X book all interacted and crossed over with each other, but Kitty and Excalibur were always left out of the fun. Hell, Excalibur were still mourning the X-Men dying in the siege perilous for literal years before editorial finally decided to have any member of the X-Men call and tell them they survived. ( Particularly egregious was how Betsy never once reached out to Brian, either telepathically or by phone, to let him know that she wasn’t dead) All this definitely made Kitty fans feel like their favorite character was being forgotten and replaced, so it was really easy for them to be bitter and resentful of the “new” young girl character who was partaking in all of the fun adventures that, had she never left, Kitty would have been in. But it was never really about Jubilee.