She's not. Fans are mocking her because she's not as overtly intimidating as some of the previous Beasts have been, being more of a conceptual threat than a physical one, and her defeat even had her crying.
The end result is many in the Fandom calling her a disgrace to the Beast Class, hence this fanart comparing her to the damegami.
Never mind that she almost won by being clever instead of being powerful, or that her defeat was only the result of some seriously BS rules-lawyering, a betrayal from her minion that wouldn't have even been effective except for dumb luck, the fact that she intended to break the hero instead of just killing him and the fact that Kiara of all people had to pull a sacrifice to rescue us.
Probably because she comes as condescending but after we started to get the upper hand, she 'sabotage' herself. Could also be because of the CG of her crying while ranting.