I think she figured since she wasn't doing it nobody else would? The game probably made Katarina look like the big boss of the harassment squad and all. But really, all that did was embolden the others. Envious twats are going to be envious and act like twats either way.
For those playing at home, this is the event that is at the beginning of the spin-off.
https://mangadex.org/title/42675/otome-game-no-hametsu-flag-shika-nai-akuyaku-reijou-ni-tensei-shite-shimatta-zettai-zetsumei-hametsu-sunzen-hen
Wahahah. And thus, another one joins the Bakarina harem. 😂😅
No wonder her nickname is Bakarina, she's so dense. Hahaha. Bit she's still lovable. Hahaha