Reposting because threads with this exact question keeps popping up every fucking week:
A speculative look of what she had done to garner so many antis and filter many potential subscribers:
>Design
One of the very basic foundations for determining the popularity of a Holo is her design. Holos agreed to have a poor design, whether overall or in the live2D model, tend to be the runt in their respective generations if it's not by a yab (e.g. Mel or Towa); Flare's squished head, Nene's chink outfit, etc.
Kiara's design is a mess of washed out bright oranges that hurts the eyes, clashing elements of phoenix, super sentai and fast food employee, and fast food being an unpopular design gimmick that rarely even works.
>Doxx
When doxxniggers started spreading the word about who she is around her debut, it turns out she has a shit ton of old antis that have been keeping an eye on her from even way back. They quickly caught up once word on the street arrived, and apparently there's a lot of figurative baggage she's carrying to have them consistently follow her around.
>Wapanese
Kiara's gratuitous self-translating during her first week didn't sit well. Not only was she unable to make a smooth conversation without interupting herself every few seconds to say what she said in nip, but it got pretty repetitive and annoying. Some think Kiara was LARPing as a JP holo that time.
>Pekora fangirling
There's simply just something that doesn't sit well with Kiara not only being the only member of her gen to list a favorite senpai on the screen, but even including a collab with her as one of her career goals and constantly squeeing every time she mentions her name. Kiara made the mistake of thinking that being a Pekora fangirl (along with being a TakaMori shipper) is a personality trait on her first week. In addition, her laugh is unsettlingly similar to Pekora, as if she's some sort of skinwalker. Needless to say, this pissed off a lot of nousagis who felt that she was emitting a creepy stalker vibe, and her getting emotional when she finally got her dream collab certainly didn't help. Speaking of emotional...
>Emotional instability
Kiara is the easiest to cry out of her genmates, whether be it from being overly sentimental or from a superchat from an anti, fanti, or KIARA MY DOG DIED. It's an incredibly awkward moment when a streamer cries on stream for reasons that aren't related to games or whatsoever; many people will hop out from the stream in turn. Unfortunately, this is also a pretty good way to signal antis that their ammo is working.
>Extroversion
In a generation of autistic introverts, Kiara is the only extrovert. And in a company of introverts, she is one of the only extroverts that can be counted on a single hand. Many people feel as if she's breaking around a dozen standard social conventions every time she speaks to her genmates, and around 4423 Japanese social norms every time she collabs with her senpais, allegedly violating "reading the room", rules of seniority, overfamiliarity, etc. Whether her genmates and senpais actually find an issue is a matter of intense debate.
>Takamori
This ship has a pretty rough start. Kiara was super active in pushing everyone to ship her with Mori, while Mori was not even a fraction as active in promoting the ship. As a result, the ship felt forced at best, and at worst, rapey. Although if the narrative that the ship was corporate-sponsored is true, the fault really lies in both of them-- Kiara for overplaying the obsessive part, and Mori for not even thinking about how tsundere would translate into a western/English context. As time went on, however, Kiara toned down a little on how much she'd push the ship, while Mori dropped the abusive tsundere act in favor of a "I love you as a homie, no homo" act. Personal rrat says she made up the Takamori thing so she can repress her Pekora fangirling by directing it to someone she's closer with, gen-wise.
I might follow this up with a retrospective evaluation, comparing stuff on the list with how Kiara is doing today.